Electrical mirror march 2017

March 2017

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Volume VI, Issue IX

Pages 82

` 80/-

ELECTRICAL MIRROR An Outlook of the Electrical & Power Industry

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Coil Winding, Stamping & Transformer Manufacturing Exhibition & Conference

Smart Meters & Smart Grids:

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Large Scope of Energy-efficiency And Conservation

Cover Story Smart Grid & Smart Meter

Focus T&M Instruments

Specical Theme Transformers

Inside

Report: Life of Transformer is 20-25 Years Special Column : High Performance Transformer Oils From Servo Guest Article : Power Quality (PQ) Solutions for Efficient Use of Electrical Power Various Case Studies on Operation and Control Schemes for Grid Sub- Station Contd...

Guest Article : On Site Measurement On Power Transformers Using The Whole Testing Toolbox

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EDITOR’S DESK

Editor

Dear Reader!

Alka Puri

Associate Editor N.P.K. Reddy Ambika Gagar

Editorial Advisor

Priyanka Roy Chaudhary

Design & Production

Sr. Designer - Mukesh Kumar Sah

National Business Head-India

Subhash Chandra Email: s.chandra@electricalmirror.net

Manager West & South India

Pradeep Kumar Email: pradeep.k@electricalmirror.net

There has been a lot of talk about “Smartgrids”, “Smartmeters”. What is smartgrid ? smart meters? And what does it mean to an average citizen of a country? How smart meters facilitate real-time pricing, automated recording of the electricity consumption and a complete eradication of errors due to manual readings and reduce labor cost and enable instant fault detection. To answer such questions, let us delve a little deeper and try to understand what are Smart Cities and how are they beneficial to us in this edition. On the other hand, in India, the demand for equipment used in power sector is multiplying at a rapid rate because of social, economic and industrial development. Govt's attempt of attaining 100% electrification across the country by 2017 would contribute to the demand for power transformers. Hence a more and brief industry review on transformers, testing and measuring instruments and transformers stamping and lamination is given in this edition.

This incisive and insightful edition provides readers with extensive reporting of key topics of interest for those involved in both utilities & manufacturing. The edition delves into essential issues of power sector particular in Indian Scenario, market size and its key trends. Our expert writers have provided feature industry review articles on various topics. The various sections in the report focus on specific segments of smart cities, smart meters, transformers, stamping and lamination and aggregates machines, and correlate these with major technological advances.

.

Sales & Marketing Neha Rajesh Kumar Hemant Chauhan

Please give us your feedback at editor@electricalmirror.net

For more details check out our Website www.electricalmirror.net & you can also visit our facebook page www.facebook.in/electricalmirror

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Praveen Chauhan Email: subscribe@electricalmirror.net Call: 011-6510 4350/ 011-2275 8660 Editor All rights reserved by all events are made to ensure that the information published is correct; Electrical Mirror holds no responsibility any unlikely errors that might occur.

Printed, published and owned by Usha, Published from 13/455, Block No. 13, Trilok Puri, Delhi-110091 and printed at Bright Tree, C-40, Gate No.-4, Okhla Industrial Area, Phase-II, New Delhi-110020. e-mail: brighttreesolutions@gmail.com

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Manufacturing & Marketing of T&M Instruments Test & Measurement Instruments for HV/EHV Substation Equipments On-line Monitoring Systems for EHV Substation Equipments & Transmission Lines Supply of complete package of T&M, Tools, Tackles & Safety Equipment to projects through dedicated Project Business Group (PBG) Calibration & Annual Maintenance Contract Services

CONTENTS March 2017

www.electricalmirror.net

Volume VI, Issue IX

Pages 82

54

Guest Article

` 80/-

ELECTRICAL MIRROR An Outlook of the Electrical & Power Industry

Power Quality (PQ) Solutions for Efficient Use of Electrical Power.

Visit us

Coil Winding, Stamping & Transformer Manufacturing Exhibition & Conference

Smart Meters Meters Smart & Smart Grids:

16 - 18, March- 2017

Bombay Exhibition Centre, India

Shylendra Kumar

Large Scope of Energy-efficiency And Conservation

Vice President, Capacitors & Filters, ABB India Limited.

58

Guest Article

Cover Story Smart Grid & Smart Meter

Focus T&M Instruments

Specical Theme Transformers

Inside

Report: Life of Transformer is 20-25 Years Special Column : High Performance Transformer Oils From Servo Guest Article : Power Quality (PQ) Solutions for Efficient Use of Electrical Power Various Case Studies on Operation and Control Schemes for Grid Sub- Station Contd...

Guest Article : On Site Measurement On Power Transformers Using The Whole Testing Toolbox

Cover Story Smart Meters and Smart grids: Large scope of energy-efficiency and conservation

10

News Update More Wind Power Projects To Go On The Block

30

Special Column High Performance Transformer Oils From Servo

40

Focus: T & M Instruments Various Routine Tests of Power Transformers Using T&M Equipment

48

Special Theme: Transformers

India’s Transformer Industry - on a Threshold Of Transformation

32

On Site Measurement On Power Transformers Using The Whole Testing Toolbox

64

Case Study of The Month

Various Case Studies on Operation and Control Schemes for Grid Sub-Station Contd. ...

68

Report: Life of Transformer is 20-25 Years

ANURAG MALHOTRA CEO – United Trafotech Pvt. Ltd. Director-GEW Trafotech Pvt. Ltd.

Product Info Flir India Testo India Meco Instruments Phoenix Contact

76 78

72 74 74 73

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ELECTRICAL MIRROR An Outlook of the Electrical & Power Industry

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News Of The Month

More Wind Power Projects To Go On The Block

Buoyed by drop in tariff to record low of Rs 3.46 per unit in the first auction of wind power, the government is mulling putting on the block more such projects next fiscal.

“Transparency which is the hallmark of the Modi government, has brought down the tariff of wind power. There will be more and more such projects on the block," Power, Coal, Mines and New & Renewable Energy Minister Piyush Goyal said.

Asked whether he is expecting wind power tariff to fall further in a more competitive environment, he said: "That is the beauty of tariff based competitive bidding. We cannot predict the tariff. It is the bidders who decide what price should be quoted.

I cannot interfere in that."

Goyal was of the view that the average wind tariff was hovering above Rs 5 per unit earlier due to feeding of rates and lack of transparency.

"We will be looking at more wind power projects auction in the next financial year. We will formalise it. We have not decided yet on the quantum as it all depends upon the states demand because the

projects are backed by them," New & Renewable Energy Secretary Rajeev Kapoor said.

The wind power tariff has been decided so far on the basis of inputs provided by power regulators such as cost of land and equipment and borrowing expenses.

However, the feed in tariff used to remain same for the periods as long as 25 years and there was no fuel cost involved as in the case of thermal power.

An industry expert said that now the feed in tariff would not survive for a very long time and there would more and more auctions in wind power segment in view of success of the first auction concluded.

The wind power tariff touched record low of Rs 3.46 per unit in first even auction conducted last week by the state- run Solar Energy Corp (SECI) where firms Mytrah Energy, Green Infra Wind Energy, Inox Wind Infrastructure Services, Ostro Kutch Wind and Adani Green Energy emerged as the lowest bidders.

The auction witnessed aggressive bidding despite an

advisory issued by industry body to avoid bold bids.

The Indian Wind Turbine Manufacturers Association had reportedly issued an advisory to some players before the auction started in view of uncertainties due to the GST implementation.

The auction assumes significance because India has set an ambitious target of having 60 GW of wind power capacity by 2022.

The wind power deployment in the country started in early 1990s. The current wind power installed capacity is nearly 28.7 GW, accounting for over 9 per cent of the total installed capacity of 314.64 GW as in January, 2017.

Globally, India is at the fourth position after China, the US and Germany in terms of wind capacity installation. The Centre has set an ambitious target of 175 GW power from renewable energy resources by 2022 and out of this, 60 GW has to come from wind power.

Govt Auctions 1,000 Mw Of Projects At Rs 3.46 A Unit India’s ambitious green energy programme took a giant leap as the country’s first wind energy auction has seen tariff dropping dramatically to Rs 3.46 per unit, mirroring the steep fall in the solar power sector and giving coal-fired plants another emission-free and competitive rival to worry about.

Solar tariffs have already fallen to Rs 2.97 per unit after a series of auctions in recent years in which companies that quoted the lowest tariff were awarded projects.

“These are exciting times, cleaner times. Our intention is to provide affordable 24X7 power, yet protect the environment and leave behind a brighter and cleaner future for the next generation,” Piyush Goyal, the minister for power, coal, renewable energy and mines.

The auction, conducted by Solar Energy Corporation of India, invited bids for 1,000 megawatts of wind projects that could be set up anywhere in the country.

The winners are Mytrah Energy (India) Pvt Ltd, Green Infra Wind Energy Ltd, Inox Wind Infrastructure Services Ltd and Ostro Kutch Wind Pvt Ltd, all of whom quoted the identical tariff of Rs 3.46 per kwH and have been awarded 250 MW each.

Adani Green Energy (MP) Ltd also quoted the same tariff. An additional project of 250 MW is likely to 10

MARCH 2017 ||

be awarded to it, even though the original auction was for only 1000 MW. There were 10 bidders in all. The rest quoted higher tariffs.

So far, wind tariffs were set by regulators of the nine states producing wind power, unlike solar projects which for some years have been auctioned and awarded to companies quoting the lowest tariff.

Wind energy tariffs have varied from a high of Rs 6.04 per unit in parts of Rajasthan to Rs 4.08 for some projects in Maharashtra. Most have varied from Rs 4 to Rs 5 a unit. Other states where wind energy is generated are Tamil Nadu, Gujarat, Andhra Pradesh, Telangana, Karnataka, Madhya Pradesh and Odisha.

The idea of holding wind power auctions had been mooted by the Ministry of New and Renewable Energy (MNRE) nearly a year ago, though three earlier attempts to hold them — once by Karnataka and twice by Rajasthan — had proved unsuccessful, with various legal issues raised by wind power associations holding them up. In October last year, however, the government issued a formal notice to auction 1000 MW of wind power projects. The last dates for submission of bids and their opening were twice deferred, until they were finally opened Earlier this month, solar tariffs dropped to an all-time

ELECTRICAL MIR ROR

low of Rs 2.97 per kwH during the bidding to set up segments of a 750 MW solar project in Rewa, Madhya Pradesh, which is likely to be the largest solar plant in the world. The lowest solar bid till then had been Rs 4 per kwH. Minister Goyal tweeted: “After solar cost reduction below Rs 3 per unit, wind power cost down to Rs 3.46 per unit through transparent auction. A green future awaits India.”

The fall in wind tariff is in some ways more significant than its solar counterpart. “There is some degree of government support in the (750 MW) MP solar project,” said Ashwini Kumar, managing director of SECI. “But for these just-auctioned wind projects, there is none.”

To encourage investment in renewable energy, the government has a scheme of providing viability gap funding (VGF) for renewable energy developers. But in the current wind auction, none of the winning developers have sought VGF. Most of the new projects are expected to come up in Tamil Nadu and Gujarat. As of December 2016, India had installed wind power capacity of 28,700.44 MW.

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ELECTRICAL MIR ROR

|| MARCH 2017 11

News Of The Month

India's Wind Power Tariffs Hit New Low In Push For Renewables

Indian wind power tariffs fell to a record low in a government-run auction on, weeks after solar power rates too hit an all-time low, as the country looks to cut chronic electricity shortages in one of the world's biggest clean energy programmes.

India, the world's third-biggest greenhouse gas emitter, has set a target of raising its renewable energy generation to 175 gigawatt by 2022, around five times current usage, to supply power to its 1.3 billion people and fight climate change.

The government push, personally monitored by Prime Minister Narendra Modi, has prompted companies to bid aggressively for solar and wind projects, pushing tariffs low enough to challenge power generated by

fossil fuels such as coal over the long term.

In an auction conducted by state-controlled Solar Energy Corporation of India (SECI) for various wind projects totalling 1 gigawatt, five companies separately quoted a tariff of 3.46 rupees ($0.0519) per unit to win the projects. “After solar cost reduction below 3 rupees/unit, wind power cost down to 3.46 rupees/unit through transparent auction," India's coal, power and renewable energy minister, Piyush Goyal, said.

Mytrah Energy , part of London-based Mytrah Group, Ostro Kutch Wind, backed by British private equity firm Actis, and Indian company Inox Wind Infrastructure won contracts for 250 megawatts (MW) each.

Green Infra Wind Energy, majority-owned by Singapore-based Sembcorp Industries Ltd, won a contract for 249.90 MW and Adani Green Energy, part of Indian billionaire Gautam Adani's infrastructure group, was awarded a 50 MW project, according to a senior SECI official and a bid document seen

by Reuters.

"The auctions have been hard fought and have led to tighter pricing than one would have foreseen even a few months earlier," said Vikram Kailas, chief executive of Mytrah Energy.

The other companies were not immediately available for comment.

Japan’s Bb Tower Picks Minority Stake In India-Focussed Igrenenergi Tokyo-based Broadband Tower K.K has picked a significant minority stake in igrenEnergi, an Indiafocused solar energy start up for an undisclosed sum.

The US-headquartered igren, with offices in Mumbai and Bangalore, will use the proceeds to expansion and technology upgradation, its chief executive Jitendra Apte confirmed.

IgrenEnergi, which counts Tata Power DDL among one of its major clients, develops innovative products which improve the economics of solar and storage, using its energy packetization architecture and proprietary

analytic platform enabled.

"We have signed an agreement and BB Tower will provide us the growth capital. The deal will also enable us our expansion in Japanese and other overseas markets,"Apte said.

BB Tower operates a portfolio of solar power plants in Japan and plans to invest further in the sector.

BB Tower has been building a relationship with University of California, San Diego (UCSD) to jointly explore, identify and develop opportunities in IOT and Cleantech.

Listed in Japan, BB Tower has a revenue of 37.13 Billion Yen (around Rs 2,200 crore) in FY 16.

The investment in igrenEnergi was made jointly

by BB Tower and GiTV - an investment fund with interest in Cleantech and Internet-of-Things.

IgrenEnergi's first product, the energy module Optimizer is currently being installed in Tata Power DDL 1 MW plant in Delhi and a few other large rooftop projects.

Founded in 2013 igrenEnergi has been incubated

by IIT-Bombay.

Wind Power Tariff Likely To Go Below Rs 4 Per Unit After a sharp drop in solar tariff to Rs 2.97 per unit, the wind power rates may also touch a new low and fall below the Rs 4 per unit mark in an ongoing auction for 1,000 MW capacity.

The tariff-based competitive bidding is being conducted by the state-owned Solar Energy Corporation of India (SECI) for wind power capacity totalling 1,000 MW for supply of power to non-windy states.

"Some of the players have quoted tariff of around Rs 4 per unit. The auction is going on and may conclude later. The wind tariff in this round of bidding is likely to fall to all-time low. It could be below Rs 4 per unit," a source said.

Although SECI has not provided any benchmark tariff, the average figure for wind power is around Rs 5.

Later last year, SECI had floated tenders for total wind power capacity of 1,000 MW. The competitive 12

MARCH 2017 ||

bidding is tariff based and will be awarded to those quoting the lowest price (power tariff).

SECI will tie up long-term power purchase agreements of developers with non-windy states to whom power will be supplied through the central transmission utility.

Under the scheme, the government will not acquire land or equipment as developers will have to do that on their own. They will also run and maintain their plants.

According to the scheme, the project capacity will be determined by SECI for each tender, but will not be less than 25 MW for a single project developer at one site.

SECI is the nodal agency for implementation of this scheme and is working on the e-bidding process followed by e-reverse auction for eligible bidders.

ELECTRICAL MIR ROR

It will also develop a suitable mechanism for project monitoring.

It has been stipulated that no separate funding will be provided by the ministry to SECI to implement this scheme. The objective is to facilitate supply of wind power to non-windy states at a price discovered through transparent bidding.

The wind power deployment in the country started in early 1990s. The current wind power installed capacity is nearly 28.08 gw, accounting for around 9 per cent of the total installed capacity of 310 gw.

Globally, India is at the fourth position after China, the US and Germany, in terms of wind capacity installation. The Centre has set an ambitious target of 175 gw power from renewable energy resources by 2022 and out of this, 60 gw has to come from wind power ||www.electricalmirror.net||

Electrical india May 2016.pdf 1 27/05/2016 08:39:25

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|| MARCH 2017 13

News Of The Month

ADB, India Ink $500 Million Loan Pact To Expand Power Connectivity

India and the ADB signed a $500 million loan pact to expand inter-regional power connectivity in the country, and strengthen transmission system to accommodate renewable energy-generation capacity.

"Expansion of inter-regional connectivity enables bulk power transfer to the southern region which has, at times, been affected by power shortages. This loan will also help strengthen the transmission system to accommodate renewable energy-generation capacity," Deputy Country Director of ADB's India Resident Mission Leonardus Boenawan Sondjaja said after signing the agreement.

The project, which is expected to be completed by

December 2020, will help build 800 kilovolt (kV) and 320 kV High Voltage Direct Current (HVDC) converter stations and 765 kV power transmission systems in India, the multilateral lending agency said in a statement.

It will also help Power Grid Corporation of India (Powergrid) add 6,000 MVA transmission capacity between Raigarh in Chhattisgarh and Pugalur in Tamil Nadu; 2,000 MVA transmission capacity between Pugalur in Tamil Nadu and North Trichur in Kerala and 3,000 MVA transmission capacity to accommodate renewable energy flows via Bikaner in Rajasthan, the statement added.

Sembcorp Gayatri Power To Commission 1,320 MW Soon Sembcorp Gayatri Power has completed construction of its (660 mw x 2) 1,320-MW supercritical thermal power project and is slated to start commercial generation in the next seven days.

Located at Nellore district of Andhra Pradesh, this project doubles Sembcorp's aggregate operational thermal power capacity in India to 2,640 MW. Sembcorp Gayatri Power is a joint venture between Sembcorp Utilities a subsidiary of Sembcorp Industries and NCC Infrastructure Holdings Ltd which is promoted by NCC Ltd and Gayatri Energy Ventures a whollyowned subsidiary of Gayatri Projects Ltd. Sembcorp Gayatri Power (formerly NCC Power Projects Limited) owns, develops and operates a 1,320-megawatt coal-fired power plant at Krishnapatnam town in Andhra Pradesh.

Built at a total project cost of approximately US$1.5 billion, the power plant utilises supercritical technology.

According to the statement, $500 million loan from ADB's ordinary capital resources will make up around 19 per cent of the $2.581 billion total project cost, with Powergrid providing counterpart financing of USD 2.081 billion.

The loan has a 20-year term, including a five-year grace period with an annual interest rate determined in accordance with ADB's LIBOR-based lending facility, it said.

Asian Development Bank (ADB), based in Manila, was established in 1966.

Tata Power's Total Operating Capacity Crosses 10,500 MW Tata Power Renewable Energy (TPREL), a wholly-owned subsidiary of Tata Power, achieved synchronisation of its 15 MW solar plant at Belampally in Telangana, thereby starting its commercial operations.

"The project was bagged by the company through a bidding process and its commissioning is in keeping with the conditions and timelines in the power purchase agreement for the project. With this development, Tata Power's total installed operating capacity crossed 10, 500 MW mark," TPREL said in a statement.

The solar plant has been built over 80 acres and includes an 18 km transmission line. Sale of power from the plant has been tied up under a 25 year power purchase agreement with the Northern Power Distribution Company of Telangana at a tariff of Rs. 5.72 per unit.

Rahul Shah, CEO, Tata Power Renewable Energy, said: "The synchronisation of the 15 MW solar plant at Belampally in Telangana marks a significant milestone in our drive to grow our portfolio of clean and renewable energy generation."

Ntpc's Total Installation Capacity Crosses 48,000 MW NTPC total power generation capacity touched 48,143 MW after its 115 MW Bhadla Solar Power Project, commissioned, the company said in a statement.

NTPC's total solar capacity now is 475 MW. It houses nearly 24 % of country's power generation capacity and has firmed up plans of setting up 10,000 MW of renewable energy projects by year 2022.

Some 23,000 MW is under implementation at 23 locations across the country including 4300 MW being undertaken under joint venture and subsidiary companies.

14

MARCH 2017 ||

At present the company operates 19 coal based, 7 gas based, 10 solar PV, one Hydro power generation facility. Additionally, it has 9 subsidiaries and joint venture power stations.

The company's maiden wind power project at Rojmal in the State of Gujarat is under implementations.

NTPC has firmed up a sustainable development plan with focus on bio-diversity, promotion of renewable energy, including plantation of trees in and around its projects, installation of rooftop solar generation capacities, rain water harvesting, water

ELECTRICAL MIR ROR

bodies rehabilitation and installation of air quality monitoring systems in major cities.

In 2016-17, NTPC created an additional carbon sink by planting 10 million trees till date. This is over and above some 22 million trees planted by the company in the vicinity of its various operating stations.

NTPC has a vision to be the world's leading power company, energizing India's growth and plans to become 130GW company by 2032 with non fossil fuel based capacity of 30%.

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ELECTRICAL MIR ROR

|| MARCH 2017 15

News Of The Month

40,000-MW Solar Park Scheme Approves By CCEA Economic Affairs (CCEA). “ "The capacity of the solar park scheme has been enhanced after considering the demand for additional solar parks from the states," he said.

"The solar Parks and ultra mega solar power projects will be set up by 2019-20 with central government financial support of Rs 8,100 crore," he added.

In a major push for solar power development in the country, a cabinet panel approved increasing the capacity of solar parks and projects from 20,000 MW to 40,000 MW. “The enhanced capacity would ensure setting up of at least 50 solar parks -- each with a capacity of 500 MW and above -- in various parts of the country," Power and Renewable Energy Minister Piyush Goyal confirmed following a meeting here of the Cabinet Committee on

The state government will nominate the Solar Power Park Developer (SPPD) and also identify the land for the proposed park, MNRE said.

Smaller parks in Himalayan and other hilly states where contiguous land may be difficult to acquire in view of the difficult terrain, will also be considered under the scheme," it added.

When operational, this solar capacity will generate 64 billion units of electricity per year which will lead to a reduction of around 55 million tonnes of carbon dioxide (CO2) per year over its life cycle, according to a statement here by the Ministry of New and Renewable Energy (MNRE).

Goyal said that for additional generation of solar power, use of areas like rooftops at airports and vacant land along runways is being considered.

The solar parks will be developed in collaboration with state governments and union territories (UTs) all of whom are eligible for benefits under the scheme.

Till date, 34 solar parks of aggregate capacity 20,000 MW have been approved which are at various stages of development, the statement added.

MNRE is already implementing a scheme for development of 25 solar parks, with an aggregate capacity of 20,000 MW, launched in December 2014, it said.

Ind-Ra Revises Wind Energy Outlook To Stable For Fy18 The increase in receivables position of wind power plants limited the headroom available to handle low wind patterns; hence, Ind-Ra has revised wind energy’s outlook to negative for FY18 from stable for FY17. With little improvements in the issues facing the toll roads sector (low inflation, slower ramp up, lower toll rate growth) and coal-based thermal power (demand-supply mismatch, increased thrust on renewables), Ind-Ra continues with its negative outlook on these two sectors.

Favorable policy actions and strong passenger growth drive the outlook revision to positive for airports for FY18 from stable, while other subsectors (solar, ports, transmission) have been maintained on a stable outlook on the back of performances largely in line with Ind-Ra’s expectations.

Ind-Ra has maintained a negative outlook on toll roads for FY18, on the expectation of sluggish traffic growth compounded by a subdued Wholesale Price Index. Ind-Ra’s analysis reveals the vulnerability of projects, especially the ones with a short operational track record (less than three years), to a 200bp reduction in base case growth rates, which would lead to impairment in debt serviceability. Road developers have found a penchant for infrastructure Investment Trusts (InvITs) – 75% of the InvITs in the listing stage are from the highway sector. Though prima facie traction in InvITs seems positive, the actual trimming of debt to the desired levels would

16

MARCH 2017 ||

be clear by 1HFY18, and discord over valuation may be a major stumbling block for InvITs. The pace of financial closures under the hybrid annuity model is marred, due to low termination payments and less equity contributions; consequently, lenders exercise caution before lending.

The negative outlook on thermal power is mainly due to suboptimal plant load factors, lack of interest for long-term power purchase agreements which has been compounded by low priority in power scheduling, and added uncertainty in awarding compensatory tariffs. Slow demand growth and abundant options for state distribution companies to tap into short-term market for meeting any temporary demand spikes have led to the lack of interest for long-term power purchase agreements.

Although steps have been taken at the policy level by the introduction of measures such as Ujwal Discom Assurance Yojana, Ind-Ra believes that reliance on state distribution companies’ errant payment cycle places issuers at a disadvantage for tapping capital markets.

Ind-Ra maintains a stable outlook for the solar power sector on the back of a stable performance, predictable nature of cash flows based on long-term power purchase agreements, decreasing panel prices, favourable debtor days, albeit with a limited operational track record. Ind-Ra believes that a combination of evolving payment security

ELECTRICAL MIR ROR

mechanism (such as creation of a payment security fund and state government guarantee) and a fall in panel prices (November 2017 yoy about 28%) will not only reduce the funding costs but also drive low solar tariffs.

Despite global macroeconomic headwinds, the airport sector recorded yet another year of a robust traffic throughput and was aided by government measures, resulting in the revision of the sector’s outlook to positive for FY18. With better-than-expected improvement in throughput levels, the capex plans of couple of airports are likely to be advanced. Delay in real estate monetisation continues to be an overhang on the Mumbai and Delhi airports. However, strong growth in aero-related revenues has negated the possible impact on revenues. Airports are well poised to refinance their debt and the agency expects issuances with elongated tenors and bullet repayments.

The outlook for seaports is maintained at stable for FY18, due to continued throughput volumes growth in line with overall economic growth. Most of the major ports recorded year-on-year growth in traffic and there were no surprises in the top commodities traded across ports compared to the previous year.

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News Of The Month

Centre Clears Rs 5,700-Crore For Hydro Project In Nepal

The Cabinet Committee on Economic Affairs has approved Rs 5723.72 crore by state-owned SJVN Limited in the 900-mw Arun-III hydropower project in Nepal, power, coal, renewable energy and mines minister Piyush Goyal said.

Financial closure for the project is expected to be achieved by September this year and it is scheduled to be completed after five years. The project, located on Arun river in Sankhuwasabha district of eastern Nepal, envisages about 70 meter high concrete gravity dam.

SJVN bagged the project through international competitive bidding and an MoU

was signed between Nepal and SJVN Limited in March 2008 for execution on build-own-operate-transfer basis for 30 years including five years of construction period. The project will offer 21.9% free power to Nepal for 25 years and generate employment of around 3000 persons in India and Nepal.

The project will provide surplus power to India strengthening power availability in the country and will also strengthen economic ties with Nepal. The power from the project shall be exported from Dhalkebar in Nepal to Muzaffarpur in India, an official statement said.

Coal To Dominate Power Sector Despite Growth In Renewables "India's power sector will remain dominated by coal over the coming decade despite significant growth in cleaner sources - notably nuclear, non-hydro renewables and natural gas," BMI Research said in a statement. According to the statement, India's power sector will remain dominated by coal over our 10-year forecast period, with coal making up a share of just less than 70% to the total power generation mix by 2026. This is roughly the same level as it is currently, with growth underpinned by the significant and continually growing project pipeline for coal-fired power facilities in the country, it said.

"We expect India to surpass the US as the world's second largest producer of coal during 2016-2020, increasing market share from 9.8% in 2016 to 12.7% by 2020. Imports will remain important for the country, as India's coal production will not meet the govt’s ambitious target of self-sufficiency, due to delays in opening up commercial mining to private players and slow approvals for new state mines," BMI Research said. "We expect global coal market to loosen and thermal coal prices to weaken from their 2016 highs, with prices to settle in a USD 60-70/tonne range over most of 2017. This trend

will be driven by China's more cautious approach to coal sector consolidation policies after provoking a policy supply shock in coal sector in 2016 which sent prices rallying," it added. "Despite the prevalence of coal-fired power generation, we expect significant growth in alternative, cleaner power sources over the next 10 years - albeit from a lower base - notably in the natural gas, nuclear and non-hydropower renewables sectors. This is in line with govt efforts to reduce pollution across the country and international pressure to boost environmental policy," it said.

Bhel Looks To Pivot From Power Sector To Transportation, Electric Vehicles

In an attempt to keep pace with the fast-changing 18

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electricity sector, state-run Bharat Heavy Electricals Ltd (BHEL), India’s largest power generation equipment maker wants to become a turn-key metro rail end-to-end solutions provider and also manufacture electric vehicles such as buses, cars, two-wheelers and boats. While Bhel has signed an agreement with Ashok Leyland Ltd and Tata Motors Ltd for developing a propulsion system for buses, the public sector unit is also seeking technical collaboration to manufacture metro rail locomotives and has initiated separate talks with Hitachi Transportation Systems, Mitsubishi Heavy

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Industries and Skoda Transportation. Experts say India presents the right opportunity for BHEL to plan its mobility solutions. With an order book of Rs 98,400 Cr that has contracted by 10% compared to a year earlier, BHEL’s order inflow has became a cause of concern. The company’s paltry order inflow of about Rs 1,300 Cr represents a steep 79% fall from a year ago. The total order inflow for the 9 months ended Dec was about Rs 6,500 Cr. While the capital goods manufacturer has a manufacturing capacity of 20,000 MW per annum its order inflow has trickled to around 6,000 MW every year. ||www.electricalmirror.net||

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|| MARCH 2017 19

News Of The Month

Outlook For India's Power Sector Negative In Fy18: India Ratings

India Ratings and Research (Ind-Ra) in its report said, it has maintained a stable negative outlook on power sector for the next FY despite an improvement in coal availability, restructuring of discoms debt and operationalisation of stuck projects. The firm in its report said it is owing to large underutilised capacities, muted demand, bunched capacity addition, soft merchant power prices, continued investments in renewable capacities, lack of PPAs and weak discoms. While credit profiles of large-sized power CoS appear to have stabilised, the sector’s return on capital employed remains unattractive and small private companies are the worst hit. With a sub-50% PLF, they have a high probability of debt default. Under the current scenario, the survival of such players is

not possible, the research firm said. It said there is a possibility of sector consolidation, which could be triggered by the new bankruptcy code and expects the PLFs of coal-based power plants to decline further in FY18 and rise thereafter, though they would continue to remain sub-65% until FY22. “Ind-Ra believes nearly 45 GW of private sector coal-based capacity running at sub-50% PLF is currently stressed, with a debt of nearly Rs 1.9 trillion. The private sector has been hit harder due to lack of PPAs for the entire capacity.

Given short-term power prices are likely to remain benign and discoms’ unwillingness to sign PPAs, these capacities are unlikely to see an increase in PLF,” the report said. “Central & state power utilities account for 60% of the 50 GW capacity,

followed by the private sector (40%). PPAs have been signed for the capacity belonging to central and state power utilities. This will put further pressure on the coal-based capacity of private power generators,” Ind-Ra said.

Government To Bring New Hydro Policy Next Fiscal: Power Secretary Pk Pujari The govt will bring out a new policy for the hydropower sector next fiscal to boost this clean source of energy, according to a senior official.

“We are working on a New Hydro Policy for quite sometime. We will do (bring) it next fiscal,” Power Secretary P K Pujari told reporters at a TERI event in last feb. The new policy also seeks to bring large hydro projects at par with smaller ones in terms of availing various benefits. At present, small hydro projects of up to 25 MW capacities are considered

as renewable energy initiatives and are eligible for various incentives by the government. Developers of large hydropower projects would get a big boost if the distinction between small and large hydro projects is removed. Of the 314.64 GW installed power generation capacity, 44.18 GW comes from large hydro projects (above 25 MW) and 50.01 GW from other renewable power generation capacities as of Jan 2017. India has set an ambitious target of adding 175 GW of renewable energy capacity

by 2022, which includes 100 GW of solar, 60 GW from wind, 10 GW from bio-power and 5 GW from small hydro-power (up to 25 MW capacity each). On energy efficiency in buildings, Pujari said, “SPARSH is a brilliant initiative to integrate green technologies for efficient green buildings.

This would chart the way forward for all the future green buildings and address the issue of energy security and energy efficiency as well.”

Budget Disappoints Power Sector: Expert Stakeholders are of the opinion that the failure on the part of Union Finance Minister Arun Jaitley to consider power sector as part of the infrastructure sector in the Union Budget presented last week will severely dampen the impressive growth initiated in the electricity installed capacity of the previous years. Electricity finance expert D. Sinha, who analysed the situation post-budget, said that while the budget gave a boost to the infra sector, it had given a shock to the power industry. The sidelining of the sector in the budget could lead to its disorientation at the very crucial stage of high expectations of growth.

‘No more sops’, “This is because the power industry 20

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pivoted around many sops. In fact, the ambitious steps taken by the government in the past years succeeded in eliminating the supply-demand gap to a considerable extent. But an abrupt end to these now can divert many investors from the scene thereby arresting the growth,” Dr. Sinha said.

To add to the woes of the sector power, cost can go up by a considerable amount due to various reasons. The budget said that the 80IA tax holiday for the sector would be discontinued from Apr 2017, disappointing solar power developers and thermal power players who were expecting extension of this clause, Dr. Sinha said. The Economic Survey was vocal on difficulties being faced by the private

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power generation sector. The industry had expected some relief in terms of corporate tax and minimum alternate tax (MAT). But there was no such mention in the budget speech. The lack of major provisions for hydro or nuclear energy was also glaring. A positive attempt in the budget was to maintain focus on rural electrification. The Finance Minister was confident of meeting the country’s ambitious 100% rural electrification target by May 2018 and he allocated a sum of Rs. 4,814 crore to its flagship scheme Deendayal Upadhyaya Gram Jyoti Yojana.

This was sure to brighten up rural India, but it was not clear how its increased energy demand could be met without ensuring a matching growth in the generation sector, Dr. Shina said. ||www.electricalmirror.net||

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|| MARCH 2017 21

News Of The Month

Nation's Problem With Coal Sector Continues: Bridge To India

In Jan 2017, India’s coal imports declined by 22% to 14 MT because of lukewarm demand from gencos. CIL, which accounts for 80% of domestic coal production, has posted its worst ever financial results for H1-FY17 as revenues declined even as expenses rose. At the same time, PLF of thermal power stations continues to be near all-time lows of under 60%. "This is all a big change from just three years ago, when coal availability was the main constraint for India’s growing power generation capacity. The reason for this reversal: while both power generation capacity and coal production have grown significantly, demand growth for power has failed to keep up," market research firm Bridge to India reports.

But power demand from more than 300 million people unconnected to or unserved by the grid is

failing to materialize despite the GoI aggressive electrification policy – aim to achieve 100% electrification by 2018 – and UDAY reform package for DISCOMs, the report says. Politics continues to dictate power pricing. Just last week, the Govt of Rajasthan decided to roll back a marginal but much-needed hike in electricity prices for agricultural consumers who pay a measly tariff of Rs 0.90 per kWh, significantly below the cost of supply. "Elsewhere, UDAY stipulated tariff hikes are not happening and, in fact, difference between the average cost of supply and average revenue realized has widened in Haryana, Madhya Pradesh, Punjab, Karnataka, Jharkhand, Bihar and Uttarakhand. Understandably, DISCOMs prefer to not supply power to loss-making consumers providing none-too-optimistic scenario for power demand." "Despite weak demand growth, the

National Electricity Plan, Dec 2016 shows that around 50 GW of additional thermal capacity is under various stages of construction. Private investors in coal mines and thermal power generation projects will face the brunt if demand doesn’t pick up. In absence of demand growth, record low tariffs and ‘must run’ status of solar plants are likely to hurt sentiment for thermal power sector very badly," says Vinay Rustagi, MD, Bridge to India. "We noted in our recent blog on Rewa solar project that falling cost provides a huge demand pull for solar power, which has suddenly become very desirable. But it is not all good news. Excess thermal capacity, poor financial condition of DISCOMs and low demand are also expected to hurt growth prospects for solar power in the long run," he said.

Budget 2017: Key Announcements And Major Misses For The Energy Sector Key announcements: One of the major energy related announcements in the budget was the merger of Indian state oil CoS to create a global behemoth. Jaitley said the govt will create an integrated public sector ‘oil major’ which will be able to match the performance of international and domestic private sector oil and gas CoS. The FM also announced a reduction in basic customs duty for LNG to 2.5% from 5%. He also said two additional strategic crude oil reserves will be created at Chandikhol in Odisha & Bikaner in Rajasthan to ramp up domestic reserves to 15 MT. Significantly, this budget also maintains the last year’s allocation for the oil ministry’s flagship scheme to provide LPG connections to poor households at Rs 2,500 Cr. Also, in an indication of things to come, Jaitley identified the ongoing rise in global crude oil prices as one of the key 3 factors that will be major challenges for the emerging economies, including India. This year’s budget also attempts to maintain focus on rural electrification flowing from Prime Minister Narendra Modi’s vision. Jaitley said India was confident of meeting its 100% rural electrification target by May 2018 and allocated a sum of Rs 4,814 Cr to its flagship scheme Deendayal Upadhyaya Gram Jyoti Yojana.

On the front of renewable energy, the FM said the govt would add 20,000 Megawatt by taking 22

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up the second phase of solar park development in the country. Stressing on the govt’s seriousness to focus more on solar energy, he said around 7,000 railway stations would be fed through solar power in the medium term and work has already begun in that respect in 300 stations.

Major misses: While the govt maintained its push for the renewable sector, the lack of any relief provision for private thermal generators struggling with huge investments stuck for want of long term PPAs left a part of the domestic industry disappointed. There was not even a mention on thermal power and coal apart from Jaitley’s announcement on rural electrification.

The Economic Survey, released on Jan 31, had pointed out to the difficulties being faced by the private power generation sector due to falling tariffs. The survey said private firms were reeling under cost-overrun pressure and PLFs and tariffs in the short-term market are not likely to rise in the near term. The industry had expected some, if not major, relief in terms of corporate tax and minimum alternate tax (MAT) for the power sector.

But there was no such mention in the FM’s budget speech. Thermal power producers had also expected some relief in terms of the Rs 400 per tonne clean energy cess that was imposed last year.

Experts also flagged the lack of major provisions

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for hydro or nuclear energy. The wind power sector had also hoped for a revision of the generation based incentive (GBI) for wind generators which is expiring on 31 March. The oil and gas industry had also demanded a revision of the high crude oil cess -- another demand that remained unheeded in this budget. Overall, experts said the budget was a mixed bag for the energy sector. Research and ratings agency ICRA said the budget has several favourable proposals such as creation of two more strategic oil reserves projects, reduction in basic customs duty (BCD) on LNG and creation of an integrated oil PSU major. “The creation of additional strategic oil reserves will boost the energy security of the nation. Reduction in BCD on LNG will make LNG more affordable to end users.

This is a credit positive for existing regasification terminal owners such as PLL, GAIL and Shell India,” ICRA said in a statement. Experts also said the idea of creation of an integrated oil major is laudable as it will strengthen the business and financial risk profile of the combined entity but integration issues, especially on the HR side, will be key challenges. Globally, the concept of stated-owned oil majors is a well established one, which confers advantages to the stakeholders.

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|| MARCH 2017 23

News Of The Month

Why Use Copper Rather Than Aluminium In Power Transformers?

Copper displays low levels of creep. Under the extreme loading and temperature conditions of distribution transformer windings, creep rates of aluminium can be up to 25 times higher than for copper. This results in aluminium wound distribution transformers having a higher propensity to failure than copper wound ones.

Copper wire terminations are less prone to failure than aluminium wire terminations. A key reason for this is the different behavior of their oxides.

Copper oxide is soft, electrically conductive, and breaks down easily. Aluminium oxide is strongly attached, hard to dislodge and electrically insulating. It also prevents non-mechanical connections such as soldering, which is only possible after applying a layer of tin, copper, or nickel.

Copper wires have no galvanic action, as they are the same element as the connectors, which are usually made of copper or brass (a copper alloy). Aluminium loses material through galvanic action, leading to a loss of contact.

Copper is harder, stronger and more ductile than aluminium, expands less and does not flow at terminations. Consequently it does not require periodic inspection and tightening of screws.

Aluminium flows away from the termination under pressure.

The use of the right grade of copper is considered

the best way to ensure high short-circuit withstand capability in power transformers, due to copper’s outstanding mechanical properties, such as yield strength and modulus of elasticity. Copper is available with a yield strength as high as 280 N/mm2 for heavy-duty transformers with frequent short-circuits such as those used for arc furnaces. External short-circuits can cause significant weakening of a transformer’s active parts, thus reducing its reliability.

Copper wound distribution transformers are invariably smaller and lighter than aluminium wound ones of an equivalent capacity and energy performance. Since the resistivity of copper is 0.6 times that of aluminium, the cross-section of the aluminium conductor needs to be 1.66 times larger than that of the copper conductor for the same resistance. This results in a larger transformer core and volume, which also leads to a larger transformer tank than for the copper design. While aluminium is lighter than copper of an equal volume, in the case of distribution transformers, this advantage is nullified by the increased volume (and thus weight) of the conductor, steel core, tank and oil.

Distribution transformers with HV windings made of copper conductors are less susceptible to metal fatigue than aluminium ones. The fatigue life of aluminium HV winding conductors has been found

to be much less than those made of copper under similar operating stress conditions. This suggests that after loosening the HV winding conductor, aluminium wound distribution transformers would fail earlier than copper wound ones.

Higher copper content in transformers improves energy performance and consequently lowers lifecycle costs in most cases. A study commissioned by the European Commission showed that the transformer design option that gives the least lifecycle cost has lower energy losses and uses substantially more copper than the respective base case.

Non-linear loads cause additional load losses in power transformers, which are influenced greatly by the transformer geometry, winding configurations, and insulation and conductor materials. In particular, thecurrent distribution is more uniform with copper conductors due to the higher conductivity.

Finally, transformers with copper windings are often less expensive to manufacture than those with aluminium windings. This is because it is not just the cost of conductor, but also the cost of magnetic steel, tank and oil needed to achieve the specified energy performance level that determines the total transformer manufacturing cost.

Schneider Electric India Powers 2 GW Of Solar Capacity In India Schneider Electric India – a global specialist in energy management and automation - has announced that it has powered more than 2 GW of solar capacity in India through its range of inverters, transformers and other medium -voltage equipment commissioned across solar projects in India under the JNNSM and other schemes.

India’s cumulative solar capacity has crossed 10,000 MW, 20% of which is flowing through Schneider Electric’s equipment. By Mar’17, the company plans to supply and commission equipment for another 500 MW solar projects, increasing its share of total capacity to 2.5 GW. The company

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is currently working on solar projects located in the states of Punjab, Rajasthan, Uttar Pradesh, Madhya Pradesh, Gujarat, Maharashtra, Odisha, Bihar, Telangana, Andhra Pradesh and Karnataka.

Schneider Electric Solar presence in the sector has grown over 50% in last one year. In 2016 alone, the company supplied equipment for more than 500 MW of solar capacity, as against 1.5 GW in last 4 years. This has been due to the rapid growth in the sector given the govt’s commitment to achieving a target of 100 GW of solar power by 2022 and its focus on clean sources of energy and reducing carbon emissions. With proven

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expertise in solar power conversion and energy management, Schneider Electric offers a complete solution for photovoltaic integration and connection including power conversion (inverters, transformers and switchgear), electrical distribution, monitoring, supervision and technical support. Schneider Electric provides the full solution from the Solar panel DC output to grid connection. Currently, company is supplying Solar equipment and products from four plants, namely at Bangalore, Baroda, Kolkata and Hyderabad, where it manufacturers solar equipment such as Solar Inverters, Ring Main Units upto 33kV, Inverter Trafo, Power Trafo, Medium Voltage HT Panels upto 33kV, and Charge controllers. ||www.electricalmirror.net||

KABEL

WIRE NAHIN, BHARAT KI NUBZ HAIN HUM.

Instrumentation & Braided Cables

Power & Control Cables

Digital Panel Meters

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|| MARCH 2017 25

Post Event : MEE

Electrical Mirror glad to share views, of his recent tour to Middle East Electricity in Dubai, as a media Partner to one of the biggest exhibition with the stall No. S1-E59 on power sector ended.

MEE 2017 held from 14th February to 16th February 2017 in Dubai World Trade Center. Followed by glorified gala dinner it was great to saw almost all the behemoth under the one platform, the nature of the MEE exhibition is to collaborate with the different ideas and exchange of these ideas worldwide, which means the translation of the upgraded ideas on a large scale, more than 1000 to 15000 participant and exhibitors from all over the world are seen to attend this Exhibition.

In the exhibition various conferences and seminar are conducted on topics which covered power sector issue and manufacturing concern globally, we would like to congratulation all the winners and runner up.

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|| MARCH 2017 27

Post Coverage

4th International Conference and Exhibition on Energy Storage and Microgrids

Next Step towards the National Energy Storage Mission, Opportunities in India Mumbai, January 2017 – The 4th annual Energy Storage India Conference and Exhibition, was another successful event that brought together 1044 industry professionals and 100+ speakers from more than 20 countries. The event came to a close on January 13, 2017 at the Nehru Centre in Mumbai, jointly organized by Customized Energy Solutions & Messe Düsseldorf India and powered by India Energy Storage Alliance.

Honorable Railway Minister, Shri Suresh Prabhu, addressed a key note at the conference emphasizing on the Make in India and E-Mobility. Shri Suresh Prabhu reaffirmed the Government’s commitment to add 175GW of Renewable Energy (RE) in the grid by 2022 and also highlighted the need of storage to augment integration of Renewable Energy. John Zahurancik, President – AES Energy Storage, delivered a key note highlighting the drivers for energy storage in India based on AES’s global experience. He announced a joint partnership agreement between AES and Mitsubishi Corporation to deliver India’s First Grid-Scale Energy Storage Array (10MW) to Tata Power DDL. The 3 day event witnessed some serious developments in the country. During the conference, Managing Director of Delta Power Solutions India - Dalip Sharma, announced expansion of Delta’s manufacturing facility in India to include production of Lithium ion batteries. John Wood, CEO – Ecoult announced a strategic partnership with Exide Industries to launch its Ultra Battery in India with a plan to set up manufacturing in 2017. Brett Galura of AES also invited Indian manufacturers to supply components for AES’s Advancion System. IESA and UL together invited

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nominations from the industry for IESA-UL energy storage standards taskforce to formulize Indiabased standards on energy storage modules and packs. Sunil Misra, Director General of Indian Electrical and Electronics Manufacturers’ Association (IEEMA) and Dr. Rahul Walawalkar, Executive Director – India Energy Storage Alliance (IESA) signed an MoU to facilitate capacity building in Energy Storage Manufacturing, Policy Frameworks and Human Resource Development.

The event observed a strong participation from key policy makers and government bodies including Ministry of Power (MOP), NITI Aayog, Ministry of New & Renewable Energy (MNRE), Central Electricity Authority (CEA), Solar Energy Corporation of India (SECI), Power Grid Corporation of India Ltd. (PGCIL), Rural Electrification Corporation (REC) and National Thermal Power Corporation (NTPC) as well as state nodal agencies. The Policy and Regulatory Session featured an eminent panel comprising of Dr. Pramod Deo (Former Chairperson, CERC), Dr. P C Pant (MNRE) and Pankaj Batra (CEA) among others. The panellists briefed the audience about various initiatives and policy changes being considered by government agencies to fast track adoption of Energy Storage and Microgrids in India.

Energy Storage India in Mumbai was a Resounding Success!

A key invite-only CXO Roundtable with key policy makers was attended by CEOs of IESA member companies to bridge the existing policy and regulatory gap in the sector and press for a national energy storage policy. The participants benefited from knowledge sharing by various international

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speakers covering USA, Canada, Europe, Russia, China, Australia, Japan and more.

Another underline of the event was European Space Agency’s announcement on partnering with IESA in leveraging space technology to support micro-grid applications and modelling. Dr. Dinesh Arora, Executive Director - REC, confirmed that over 700 minigrids are in process of tendering in the country. He requested the industry to keep up the pace of technology innovation for bottom of pyramid. The Microgrid Initiative for Campus and Rural Opportunities (MICRO) initiative by IESA was demonstrated during the conference, explaining its unique value propositions for various stakeholders such as investors, developers and equipment suppliers catering to microgrid market.

India saw 46MW of opportunities in 2016 and looks forward to over 100MW of RFPs for 2017. This includes projects by SECI, NTPC, PGCIL, NLC, CEL and REIL. Dr. Bharath Reddy of SECI declared that a total of 13 bids were received for the recently concluded 2x5MW Storage + 50MW Solar PV project in Andhra Pradesh Solar Park.

Energy Storage India 2017 also introduced its first Industrial Awards, hosted by IESA. The awards were divided as – “Energy Storage Company of the Year” was awarded to Panasonic for deploying over 130MWh of Li-ion Batteries for Telecom and Banking applications in India, “Energy Storage Project of the Year” was awarded to PGCIL for their Puducherry project, “Technology Innovation of the Year” was awarded to Pluss Advanced Technologies for their revolutionary work in Phase Change Materials, and “Microgrid Company of the Year” was awarded to Husk Power for electrifying 15,500 households in India.

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Special Column

HIGH PERFORMANCE TRANSFORMER OILS FROM SERVO -Nitish Mittal, Sr. Mgr. (TS), Indian Oil Head Office

Transformer oils also known as insulating oils are prepared from highly refined mineral oils. These oils serve mainly two purpose- one as liquid insulation in electrical power transformer and two, dissipate heat of the transformer i.e. act as coolant. In addition to these, transformer oils help to preserve the core and winding as these are fully immersed inside oil and prevent direct contact of atmospheric oxygen with cellulose made paper insulation of windings, which is susceptible to oxidation.

High voltage transformers are having oil tank above it, often experience gas build up inside the transformer because of overheating of the oil. This gas build-up increases the pressure inside the transformer results in tripping the protective circuit breaker. The transformer oil must have low volatility and high thermal stability to ensure reduced gas formation at high temperature.

Generally there are two types of Transformer Oils available in market Paraffin base Transformer Oil & Naphthenic base Transformer Oil. The basic difference between paraffinic & naphthenic transformer oils can be summarised in the following table:-

procedure. The test result for Servoelectra shows superior thermal /oxidation stability and excellent electrical properties of aged oils after the oxidation tests.

- Compatibility with Construction Materials: Servoelectra when evaluated with various construction materials i.e. crape paper, insulating paper, cotton paper and press board as per ASTM D 3455 test procedure and also with increased severity (by increasing the size of construction materials to four times), is found to be compatible & it retains the general physico-chemical and electrical properties of the oil.

Other than above, Servoelectra possesses superior cooling property, higher flash point, lower pour point & low aromatic content. It is free from Poly Chlorinated Biphenyls (PCBs).

Servoelectra is approved and well accepted by Transformer OEMs and users for use in generation and transmission transformers of EHV (Extra High Voltage) class up to 400 kV and distribution transformers to various ratings. It has validation from reputed Transformer OEMs like BHEL, Crompton Greaves, ABB, Schneider Electric, Voltamp, Marsons Electrical, Servomax India, Tesla Transformers and many others, as well as State electricity boards like APGENCO/APTRANSCO/APCPDCL/APNPDCL, TNEB, JSEB, UHBVN/DHBVN, MAHADISCOM, PVVNL, KSEB, APDCL, Power plants like Anpara, Parichha, Torrent Power, DVC, Renusagar etc. and many other industries like TISCO, Coal India, ONGC, Hindalco, HAL, BILT, Usha Martin etc.

Various ranges of Transformer oils available with IndianOil are given below:-

Property

Transformer Oil-Paraffinic Transformer Oil- Napthenic

Low temperature properties

Good/ Satisfactory

Excellent

Viscosity-temperature characteristics

Excellent

Poor

Oxidation & thermal stability

Excellent

Satisfactory

Heat Capacity & Thermal Conductivity Excellent

Satisfactory

Solvency

Satisfactory

Good

Sludge dispersion characteristics

Good/ Satisfactory

Excellent

Volatility

Low

High

Product

Meeting Spec. Requirements

Flash point

High

Low

Polarity

Low

High

Servoelectra

IS 335 - 1993

Servoelectra Plus

IS 12463 - 1988

Servoelectra Super

BHEL TRE 158

Servoelectra UX

IEC 60296 (Uninhibited) -2012, NTPC, BS 148 (C I & C II)

Servoelectra LPT

IEC 60296 (Trace Inhibited)

Servoelectra IX

IEC 60296 (Inhibited) -2012, BS 148 (C IA & IIA)

Servoelectra Power (I)

PFCIL

Modern refining methods using hydro-catalytic processes lead to manufacturing of new generation paraffinic transformer oil base stocks (Group II). Such base stocks inherently possess superior thermo-oxidative stability, adequate pourability, lower volatility and higher flash point. These base oils are used for production of high performance transformer oils `SERVOELECTRA’, meeting Indian standard IS 335 (un-inhibited type).

- Superior Electrical Properties: Electrical properties of transformer oils are assessed by various standard tests including Dielectric strength/ breakdown voltage (BDV), dielectric dissipation factor (tan delta) and specific resistivity. Dielectric strength refers to the ability of the transformer oil to withstand electrical stress without affecting the quality of the oil. The electrical properties of insulating oils depend on the level of refining of the oil as well as the presence of moisture/impurities or external contaminants. Servoelectra has excellent electrical properties.

- Excellent Oxidation Characteristics: The ability to resist oxidation at elevated temperatures in presence of oxygen is assessed by the oxidation test as per test procedure appended in the Annexure C of IS 335. In this test, degree of oxidation is estimated by determining the amount of sludge generated and the neutralization value of oxidized sample. Another test for checking the oxidation characteristics of transformer oil is open beaker oxidation test as per IS 12177 test 30

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Servoelectra is manufactured at State-of the art facilities at Taloja, Silvassa & Kolkata, which are ISO 9001 & IS 335 certified.

To ensure desired performance of the Transformer oils, regular monitoring of oil quality particularly for break down voltage and moisture content testing is required. Regular maintenance of the system by way of checking the breather seal, centrifuging and dehydration of oil will help in maintaining the quality of the Transformer oil as well as the performance of the transformer oil. This condition monitoring will also help in establishing the optimum drain interval of the oil. Indian Oil offers oil condition monitoring as well as management through its Total Fluid management program.

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Cover R Y

O ST

Smart Meters and Smart grids: Large scope of energy-efficiency and conservation

"We all aware of the smart meter how it works as a

spy for the usage of your electricity over the month, hence the author tries to convince the reader through his write up on Smart Meters and Smart Grids, how their efficiencies are likely to work on the energy conservation and energy efficiencies by covering the topics on features and its advantages on Smart Meters also including many more topics, enjoy reading."

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Smart Cities?

There has been a lot of talk about “smart cities”

lately. Government of India has declared that India is planning to have 100 new smart cities. Not only India, countries all over the world are striving to build smart cities in order to increase productivity and socio-economic growth of the country. After seeing such enthusiasm around smart cities, one starts wondering- what is a smart city? Why India and so many other countries are trying to build smart cities. And what does it mean to an average citizen of a country? Does the “concept of smart cities” pertain only to commercial spaces and industries or would it bring a change in his/her lifestyle as well? To answer all these questions, let us delve a little deeper and try to understand what are smart cities and how are they beneficial to us.

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sustainability and a clean environment. A smart city will have a global responsibility towards the environment and will make sure that the investments made in the field of development does not bring results at the cost of a polluted environment. So in a smart city, there will be efficient & environment friendly ways of transportation, waste- management, electricity transmission & distribution without compromising the overall quality of the entire system. Although there are several aspects of a Smart City, but in this article we would like to highlight some important things from the “Energy” perspective. Although the concept of smart cities houses many components, here we will try to understand the significance of smart cities from an “energy” perspective. A smart city, as discussed earlier, will be able to optimize the electricity consumption of the city by being able to record the real-time data pertaining to different residential, commercial and industrial spaces. A smart city is equipped with smart grids which facilitate this collection and transferring of electricity related data throughout the city, free from all hassles and wouldn’t even require manual labor. So an individual living in a smart city essentially would have excellent control over his/her electricity consumption and ultimately would be able to optimize the expenses incurred on the electricity bills. This not only would help curb the unbridled electricity consumption but also ease the enormous pressure on the sources of electricity.

A smart city uses digital technology to improve the performance of the various resources to enhance the overall productivity and well-being of the city. The objective of a Smart City is to use digital communication and technology to optimize the usage of resources like: Energy, Water, Roads/ Infrastructure and improve Governance, Transportation, Health Care and Waste Management. The advent of the concept of smart cities rides on the tremendous increase in the usage of the tools of digital technology like smart phones, Internet of Things (IoT), cloud based services and so on which open up different channels of communication and encourages flexibility and better implementation of rules and regulations. Smart cities are equipped to handle the issues of growing population, climate change, economic stress in the most efficient manner using different tools of communication and information technology. But when we talk about smart cities, it is not economic development only we are talking about; smart cities have a much bigger role to play in the current global scenario. Concept of smart cities houses 3 key components: Productivity, Inclusion & Resilience (sustainability).

In short, smart cities enhance the productivity of Smart Grids? the city along-with increasing the contribution of Suppose there are two regions namely A and B, in all the citizens in the overall development of the a city. The total power capacity allotted to region A society. Also, the concept of smart cities supports is 20 kVA and the total capacity allotted to to region B is 10 kVA. But the actual consumption of region

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A is 12-13 kVA and for region B, the consumption of power is almost 10 kVA and sometimes it even overshoots the total power capacity of region B. Now in case of traditional electricity grids, there is a lot of power that is not being used, which can be used by those regions which have a shortage of power supply. On the other hand, there may be a system failure in the second case, when the actual power consumption is consistently around the total capacity provided to that region, and sometimes even crosses the maximum capacity. Smart grids present an elegant solution to this problem. Since the whole process of power transmission and data collection is automated, when a smart grid observes that there is a skewness in the electricity consumption of the two regions, it automatically re-distributes the power according to the usage of the regions, thereby removing any imbalance in the electricity distribution and consumption and saving a lot of energy, by minimizing the scope of wastage. Smart grids are an advancement of the electricity grids that are being used currently. A smart grid is an electrical grid that uses modern technology (digital or analog) to collect and communicate electricity related information of both the suppliers and consumers. It not only enhances efficiency and reliability, but also improves the production and distribution of electricity to the consumers. The process of installing a smart grid necessarily means technical re-designing of the infrastructure at different levels. One such measure means replacing the existing electronic meters (or electromechanical meters) with smart meters, to enhance the sustainability and efficiency of the entire electrical system.

Advanced Metering Infrastructure (AMI)/Smart Meters?

We are used to seeing either an electromechanical meter (with a rotating disk to record the electricity consumption) or an electronic meter (with digital 34

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figures) at our houses, offices or any other property to measure our electricity usage. Typically, at the end of the month (or months) a representative of the utility (the company/organization that provides electricity to you) comes to the property, observes the reading in the meter and subsequently you get the bill for the units of electricity you have used in that period of time. And that’s all. As far as the customers are concerned, there does not seem to be any problem with this mechanism. But still, since manual labor is involved, there are bound to be some errors/irregularities. In order to minimize the chances and number of mistakes and maximize the efficiency and performance of the whole system, smart meters step in the picture. A smart meter is an electronic measurement device installed by the utility to maintain a two-way communication between the consumer and the utility and also manage the electrical system of the consumer. A smart meter is capable of communicating the real time energy-consumption of an electrical system in very short intervals of time to the connected utility. In the electronic meters/electromechanical meters, the cumulative number of electricity units was recorded at the end of a month (or more) whereas a smart reader is connected to the utility which is capable of transmitting the electricity usage on a real-time basis. Smart meters thus facilitate real-time pricing, automated recording of the electricity consumption and a complete eradication of errors due to manual readings and reduce labor cost and enable instant fault detection.

The Smart Grid is not just a compilation of smart meters, wind, solar, or plug in electric vehicles, but is essentially the modernization of the transmission and distribution aspects of the electrical grid. Functionally, it is an automated electric power system that monitors and controls grid activities, ensuring the efficient and reliable two-way flow of electricity and information between power plants and consumers—and all points in

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between from customer preferences to individual appliances/ equipment. A Smart Grid monitors electricity delivery and tracks power consumption with smart meters that transmit energy usage information to utilities via communication networks.

The two-way nature of Smart meter systems allows for sending commands to operate grid infrastructure devices, such as distribution switches and recloses to provide a more reliable energy delivery system known as Distribution Automation (DA).

Smart meters are often promoted as a route for energy savings, real-time pricing, automated data collection, avoiding human errors due to manual readings which would ultimately reduce labour costs, diagnosis and instantaneous fault detection allowing for predictive maintenance resulting in a more efficient and reliable distribution network.

Basic Types Of Smart Meter Systems: There are two basic categories of smart meter system technologies as defined by their local area network (LAN).

They are radio frequency (RF) and power line carrier (PLC). Each of these technologies has its own advantages and disadvantages in application.

The utility selects the best technology to meet its business needs. Factors that influence the selection of the technology includes evaluation of existing infrastructure, impact on legacy equipment, functionality, technical requirements as well as the economic impact to the utility’s customers. The selection of the technology requires a thorough evaluation and analysis of existing needs and future requirements into a single comprehensive business case.

Advanced Metering Infrastructure (AMI) facilitates monitoring and measurement of consumer information through Smart Meters installed at customer premises. The information is transferred to utility control centre through communication mode such GPRS / PLC / RF. Smart meters will also enable Time of Day (TOD) and Critical Peak pricing (CPP)/Real Time Pricing (RTP) rate metering and ||www.electricalmirror.net||

monitoring based on energy consumption.

Features of AMI are:

1. Recording energy consumption data for consumer and utility (kWh, kVARh voltage, pf, max demand etc.)

2. Automatically send the consumption data to the utility at predefined intervals.

3. Time-based pricing signal for Demand Response.

4. Bi-directional communication ability.

5. Net metering to facilitate integration of Distributed Generation in the form of Rooftop Solar etc.

6. Loss of power (and restoration) event notification.

7. Remote Load limiting for Peak Load management.

8. Remote connection and disconnection of individual supply.

9. Energy prepayment.

10. Reporting meter tampering in real time to the utility.

11. Communications with other intelligent devices in the home.

12. Gateway to communicate other meters data (Gas/water)

Advantages of AMI are:

1. Accuracy in meter reading: In case of electromechanical/electronic meters, the meter readings have to be read by a representative of the utility. Smart meters automatically transmit the readings to the connected utility.

2. Data recording: Conventional meters only record the electricity consumption of a system, and not when and how the electricity is used. Smart meters record real-time data corresponding to the

electricity consumption. It means that they also record the time and patterns of electricity consumption.

3. Real time tracking: What’s really nice about these meters is that consumers can go online and check out their electricity usage patterns and make changes to their consumption accordingly. In this way, smart meters offer a strong control to the consumers over their usage.

4. Automatic outage detection: A person having a conventional meter has to call utility whenever there is a power outage whereas in case of smart meters, there is an automatic outage detection as they are constantly synchronized with the electric grid.

5. Better service: As smart meters are directly connected to the utility, it becomes simple to connect/ disconnect power for a particular house/property, saving the need of a technician going to the house in person and connect/disconnect the supply.

Basic Architecture of Smart Meter

Smart meter systems are an integral part of the Smart Grid infrastructure in terms of data collection and communications. The smart meters collect data locally and transmit via a local area network to a data collector. The collector retrieves the data and may or may not carry out any processing of the data. Data is transmitted via a WAN to the utility central collection point for processing and use by business applications.

Since the communications path is two-way, signals

or commands can be sent directly to the meters, customer premise or distribution device. The general block diagram-showing the main and auxiliary sections- of a smart meter design is shown in below figure. Depending on the application, energy, gas, or water metering, one or more sensors may be interfaced to front end electronics, an energy source with the associated power management circuitry, a communication node, and a microcontroller for system management.

There are 3 main areas of a smart meter design namely- the power system, microcontroller, and communications interface. The power system has a switched mode power supply and battery backup to ensure that the metering electronics remain powered even when the main line is disabled. A Microcontroller Unit (MCU) includes an Analogto-Digital Converter (ADC) and Digital-to-Analog Converter (DAC) to provide intelligence. A wired or wireless communication interface allows the meter to interact with the rest of the grid and in some cases the end user’s network. The advantages of this technology include acceptable latency, large bandwidth and typically operates at higher frequencies. The disadvantages include terrain and distance challenges for rural areas, proprietary communications and multiple collection points.

The hardware design and architecture of a smart meter, a wireless sensor and actuator node which can monitor current consumptions of attached appliances and control their mains connection. Based on the low-cost reprogrammable components, smart-meter has been designed as a versatile experimental platform. Specific sensing or actuation behavior can be easily integrated through the reprogrammable character of the used microcontroller to raise user awareness for their energy consumption.

Basic Hardware Design of Smart Meter

A smart meter is comprised of sensitive circuitry and may support numerous communications protocols. ||www.electricalmirror.net||

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In addition, there are sensing and circuit protection circuits included in the design of the smart meter in which resistors are naturally a fundamental part of the electronic design. The metrology AFE revenue-grade measurements rely on the accuracy of series resistors for current sampling. A complete implementation include power line communication to the electricity meter and low power wireless communication from the electricity meter to other utility meters. Two communication scenarios are prominent here in the first scenario, the Advanced Metering Infrastructure (AMI) utility-network transceiver (the physical element that connects the meter to the communication channels back to the utility) would be located in the utility domain whereas the home area network (HAN) transceiver (the physical element that connects the meter to the communication channels in the home) would be in the customer domain. The second scenario allows direct utility access to customer-owned devices

54 million.

4. Commercial and other establishments expected to be connected to electric grid by 2020 25 -30 million.

AMI Implementation and Maintenance on Services Model

General Issues

When smart meters were first installed in some western countries, some unanticipated reactions of people surfaced. One such reaction pertained to the ability of the utility to disconnect the power supply of people who did not pay their electricity bills, without sending a representative to the concerned property.

Although on the utility’s part, it is not unjustified to do so, but such a practice of remote disconnection of power-supply would put low-income consumers at a risk. There were also some concerns that were raised regarding the detailed information that the smart meters glean about the energy usage of people. Again, this access to this information is fairly innocuous, but some claimed that by having such detailed information on the usage patterns of consumers would gain knowledge of the consumers’ habits like at what time nearly all the people are at home, at what time people are watching television, are there any inhabitants at a property at a particular time and so on which might then be used by third parties.

ISGF: AMI Rollout Strategy for India

AMI Rollout framework on Leasing and Services model: AMI Considering huge capital investment required for the rollout of millions of smart meters and the present financial health of the electricity distribution companies (Discoms), it is proposed to undertake the AMI rollout on ‘Leasing’ and ‘Service Model’ as explained below: The electricity consumer statistics in India are (approx.): 1. Total no. of electricity connections 250 million.

2. Total no. of unmetered connections 25 million.

3. Households without electricity connection 36

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manufacturer nor the Discom will be able to fund the program. Hence in the interest of faster roll out, it is proposed to have a financial intermediary (a bank, PFC or other financial institutions) who will buy meters and communication devices from the manufacturers and lease it to the Discoms against a monthly rent for a period of ten years.

Meter Procurement on Leasing Model

It is proposed to engage a nodal agency who will issue tender for procurement of smart meters as per BIS Standards (IS 16444 and IS 15959 – Part 1 and 2). The rates will be finalised on annual basis. Manufacturers with BIS-certified smart meters may be empanelled with rates of meter and different communication devices which the Discoms can choose based on their unique requirements. The cost of the smart meters and cost of the communication devices/ Network Interface Cards (NIC) to be specified separately. Once manufacturers are empanelled, capacities declared and rates finalized (valid for a specified duration), each Discom can buy from these empanelled organisations provided they have the capacity to supply according to the rollout schedule of the Discom. Since the quantity of the meters to be installed is in tens of millions and the capital expense will be large, neither the meter

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AMI involves expertise in three distinct domains, namely, metering, telecommunication and information technology (including both software and hardware).

Experience from around the world shows that no one agency could master these distinct components of AMI. Early-mover utilities tried to invest and own all these systems and have seen mixed results.

All successful AMI projects have a strong system integrator playing the major role either as a prime contractor or as a utility’s consultant (like a Master Systems Integrator) who tests and approves each sub-components of the AMI system and ensures its interoperability and integration with other utility applications. We propose to appoint a Metering Services Agency (MSA) who will be responsible (along with their sub-contractors and associates) for a variety of functions related to implementation of AMI and its maintenance. Typical scope of services of a MSA would include: 1. Testing and certification of the meter and communication devices to be procured by the Discom for the defined scope of AMI in a given area/town with chosen communication technology/technologies.

2. Taking delivery of meters & communication devices from the Discom and installing them at customer premise; and return of old meter to the Discom.

3. Establishing and maintaining the last mile communication connectivity for smart meters for a period of at least 10 years. ||www.electricalmirror.net||

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4. Selecting the appropriate communication technology for providing a WAN/backhaul network.

5. Leasing of bandwidth (wherever required) and maintaining for 10 years.

6. Sizing of software and hardware of HES, MDMS and associated IT systems, and providing O&M services for at least 10 years. The MDMS, HES and associated IT systems to be housed at Discom premises or hosted in a sovereign public cloud.

7. Integrating, testing and commissioning of the entire AMI system.

8. Creation of middleware (if required) and integration of MDMS with middleware.

9. Integration of MDMS with other systems such as billing, collection, connection/ disconnection, OMS etc.

10. Ensuring availability of complete AMI system at mutually agreed Service Level Agreements (SLAs)

3.

4.

5.

6.

ISGF Strategy for large scale deployment of smart meters

1. All feasible communication technologies may be allowed to operate in order to encourage innovation in view of the fact that the communication technologies advance much faster compared to other electrical technologies.

2. IPv6 shall be made mandatory as this is in line with the IPv6 roadmap of the Ministry of Communications & IT, which states that: a. All new service provider-owned Consumer Premises Equipment (CPE) deployed after June 30, 2014 to be IPv6 ready. b. Replacement/upgradation of 25% of CPEs

by December 2014. c. Replacement/upgradation of 50% of CPEs

by December 2015. d. Replacement/upgradation of 75% of CPEs

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7.

by December 2016. e. Replacement/upgradation of 100% of CPEs

by December 2017.

MoP may advise all Discoms to strictly abide by the new BIS meter standards. Hence, all meters procured by Discoms may be IS 16444 and IS 15959 compliant.

A neutral agency may be appointed to assess the efficacy of the various communication technologies deployed in successful AMI projects around the world and in pilot projects in India and prepare a technology selection guide and roadmap for smart meter deployments in the country.

Neutral agencies may be engaged for customer awareness and engagement programs related to smart metering and smart grids.

Discoms to deploy smart meter on such feeders that have a large number of customers with monthly consumption greater than 500 kWh. Subsequently, customers with monthly consumption lesser than 500 kWh may be deployed. Deployment to be done on feeder-wise and NOT customer-wise so that the last mile communication network can be established and maintained at reasonable cost.

As per IS 16444, the communication module has to be a part of the smart meter (either inbuilt or pluggable units). Hence retrofitting will not be possible. This was a decision taken by the technical committee at BIS as the stakeholders cited the following concerns if the communication module is retrofitted on existing meters.

Smart Grids can be an anchor tenant for the Smart City

After all, nothing else works without electricity.

The design of communications should obviously cater to all Smart Infrastructure of the city. We

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must take bold steps towards Smart Grids which can provide solutions to Smart Cities. If one were so inclined, how does one eat an elephant? One bite at a time. ISGF along with our members and other key stakeholders conducted 2 brainstorming workshops and prepared Standard Framework for Infrastructure Domains of a Smart City. We anchor around Smart Grid for the development of Smart Cities in India because digital assets created under various programs can be directly leveraged by other service providers and utilities to build smarter infrastructure. All state owned electricity distribution companies (Discoms) in India are implementing a set of basic IT and Automation solutions under the ongoing R-APDRP scheme of the Ministry of Power. Some of the digital assets created under this program that already covers 1411 towns can be leveraged to build smarter cities at lower marginal costs. List of digital assets and smart infrastructure created under various schemes of Ministry of Power are as follows: 1. GIS Map of the Towns 2. Billing and Customer Relationship Management (CRM) Systems 3. SCADA/DMS System 4. Common Command and Control Centre 5. Outage Management Systems (OMS) and Mobile Workforce Management (MWFM) 6. Application Integration List of Selected 20 Smart Cities for Phase 1 in Smart Cities Mission - Bhubaneswar (Orissa), Pune (Maharashtra), Jaipur (Rajasthan), Surat (Gujarat), Kochi (Kerala), Ahmedabad (Gujarat), Jabalpur (Madhya Pradesh), Vishakhapatnam (Andhra Pradesh), Solapur (Maharashtra), Davanagere (Karnataka), Indore (Madhya Pradesh), New Delhi (Delhi), Coimbatore (Tamil Nadu), Kakinada (Andhra Pradesh), Belgaum (Karnataka) Udaipur (Rajasthan), Guwahati (Assam), Chennai (Tamil Nadu), Ludhiana (Punjab), Bhopal (Madhya Pradesh).

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Focus : T&M Instruments

Various Routine Tests of Power Transformers Using T&M Equipment

The structure of the circuit equivalent of a practical transformer is developed earlier. The performance parameters of interest can be obtained by solving that circuit for any load conditions. The equivalent circuit parameters are available to the designer of the transformers from the various expressions that he uses for designing the transformers. But for a user these are not available most of the times. Also when a transformer is rewound with different primary and secondary windings the equivalent circuit also changes.

In order to get the equivalent circuit parameters test methods are heavily depended upon. From the analysis of the equivalent circuit one can determine the electrical parameters. But if the temperature rise of the transformer is required, then test method is the most dependable one. There are several tests that can be done on the transformer; however a few common ones are discussed here. Routine test of transformer is mainly for confirming operational performance of individual unit in a production lot. Routine tests are carried out on every unit manufactured. All transformers are subjected to the following Routine tests viz‌ Insulation resistance Test, Winding resistance Test, Turns Ratio / Voltage ratio Test, Polarity / Vector group Test, No-load losses and current Test, Short-circuit impedance and load loss Test, Continuity Test., Magnetizing Current Test, Magnetic Balance Test, High Voltage Test, Dielectric tests (Separate source AC voltage/ Induced overvoltage/ Lightning impulse tests), Test on On-load tap changers, where appropriate.

Insulation Resistance Test

Purpose and Instruments: Insulation resistance test of transformer is

essential to ensure the healthiness of overall insulation of an electrical power transformer. And instruments used are LT System: 500V / 1000V Megger. & MV / HV System: 2500V / 5000V Megger.

Type tests: Type tests are tests made on a transformer which is representative of

other transformers to demonstrate that they comply with specified requirements not covered by routine tests: Temperature rise test (IEC 60076-2) and Dielectric type tests (IEC 60076-3).

Special tests: Special tests are tests, other than routine or type tests,

agreed between manufacturer and purchaser viz‌ Dielectric special tests, Zero-sequence impedance on three-phase transformers, Short-circuit test, Harmonics on the no-load current, Power taken by fan and oil-pump motors, Determination of sound levels, Determination of capacitances between windings and earth, and between windings, Determination of transient voltage transfer between windings, Tests intended to be repeated in the field to confirm no damage during shipment, for example Frequency Response Analysis.

Pre-commissioning Tests: The Test performed before commissioning

transformer at site is called pre commissioning test of transformer. These tests are done to assess the condition of transformer after installation and compare the test results of all the low voltage tests with the factory test reports.

All transformers are subjected to the following Pre commissioning tests viz‌ IR value of transformer and cables, Winding Resistance, Transformer Turns Ratio, Polarity Test, Magnetizing Current, Vector Group, Magnetic Balance, Bushing &, Winding Tan Delta (HV), Protective relay testing , Transformer oil testing, Hipot test.

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Test Procedure: First disconnect all the line and neutral terminals of the

transformer. Megger leads to be connected to LV and HV bushing studs to measure Insulation Resistance value in between the LV & HV windings.

Megger leads to be connected to HV bushing studs & transformer tank earth point to measure Insulation Resistance IR value in between the HV windings & earth. Megger leads to be connected to LV bushing studs & transformer tank earth point to measure Insulation Resistance IR value in between the LV windings and earth.

It is unnecessary to perform insulation resistance test of transformer per phase wise in three phase transformer. IR values are taken between the windings collectively as because all the windings on HV side are internally connected together to form either star or delta and also all the windings on LV side are internally connected together to form either star or delta.

Measurements are to be taken as follows: Type of Transformer

Testing 1

Testing 2

Testing 3

Auto Transformer

HV-LV to LV

HV-IV to E

LV to E

Two Winding Transformer

HV to LV

HV to E

LV to E

Three Winding Transformer

HV to LV

LV to LV

HV to E & LV to E

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Oil temperature should be noted at the time of insulation resistance test of transformer. Since the IR value of transformer insulating oil may vary with temperature. IR values to be recorded at intervals of 15 seconds, 1 minute and 10 minutes. With the duration of application of voltage, IR value increases. The increase in IR is an indication of dryness of insulation.

Absorption Coefficient = 1 minute value/ 15 second value.

Polarization Index = 10 minutes value / 1 minute value Tests can detect: Weakness of Insulation.

DC Resistance or Winding Resistance Test

Purpose and Instruments: Transformer winding

resistance is measured. To check any abnormalities like Loose connections, broken strands and High contact resistance in tap changers. To Calculation of the I2R losses in transformer. To Calculation of winding temperature at the end of temperature rise test of transformer. The Resistance of HV winding LV winding between their terminals is to be measured with Precision milliohm meter/ micro ohm meter/ Transformer Ohmmeter / Wheatstone bridge / DC resistance meter.

same. The measured resistance should be corrected to a common temperature such as 75OC or 85OC using the formula: RC=RM x ((CF+CT)/(CF+WT)) where RC is the corrected resistance, RM is the measured resistance. CF is the correction factor for copper (234.5) or aluminum (225) windings. CT is the corrected temperature (75OC or 85OC). WT is the winding temperature (OC) at time of test. Before measurement the transformer should be kept in OFF condition at least for 3 to 4 hours so in this time the winding temperature will become equal to its oil temperature. To minimize observation errors, polarity of the core magnetization shall be kept constant during all resistance readings.

Voltmeter leads shall be independent of the current leads to protect it from high voltages which may occur during switching on and off the current circuit. The readings shall be taken after the electric current and voltage have reached steady state values. In some cases this may take several minutes depending upon the winding impedance.

The test current shall not exceed 15% of the rated current of the winding. Large values may cause inaccuracy by heating the winding and thereby changing its resistance. For Calculating resistance, the corresponding temperature of the winding at the time of measurement must be taken along with resistance value.

For Oil immersed transformers: the transformers should be under oil and without excitation for at least three hours. In case of tapped windings, above readings are recorded at each tap. In addition, it is important to ensure that the average oil temperature (average of the top and bottom oil temperatures) is approximately the same as the winding temperature. Average oil temperature is to be recorded. Measured values are to be corrected to required temperatures. As the measurement current increases, the core will be saturated and inductance will decrease. In this way, the current will reach the saturation value in a shorter time.

After the current is applied to the circuit, it should be waited until the current becomes stationary (complete saturation) before taking measurements, otherwise, there will be measurement errors. The values shall be compared with original test and result which varies with the transformer ratings.

Test Acceptance criteria: DC Resistance Should be <=2% Factory Test or Test Current <10% Rated Current Test can detect Short Turns, Loose Connection of bushing, Loose Connection or High Contact Resistance on Tap Changer and Broken winding stands.

changes in temperature, some precautions should be taken before the measurement is made.

For Delta connected Winding: for delta-connected transformer, the resistance should be measured for each phase (i.e. R-Y, Y-B & B-R). Delta is composed of parallel combination of the winding under test and the series combination of the remaining winding .It is therefore recommended to make three measurements for each phase to-phase winding in order obtain the most accurate results. For Delta connected windings, such tertiary winding of auto-transformers measurement shall be done between pairs of line terminals and resistance per winding shall be calculated as per the formula: Resistance per Winding = 1.5 X Measured Value

out Open Circuited turns, Short Circuited turns in Transformer winding. The voltage ratio is equal to the turn’s ratio in a transformer (V1/V2=N1/N2).

Using this principle, the turn’s ratio is measured with the help of a turn’s ratio meter. If it is correct , then the voltage ratio is assumed to be correct.

This test should be made for any new high-voltage power transformer at the time it is being installed.

With use of Turns Ratio meter (TTR), turns Ratio between HV & LV windings at various taps to be measured & recorded. The turn’s ratio is measure of the RMS voltage applied to the primary terminals to the RMS Voltage measured at the secondary terminals. R = Np / Ns, Where, R=Voltage ratio. Np=Number of turns at primary winding.

Ns= Number of turns at secondary Winding. The voltage ratio shall be measured on each tapping in the no-load condition. And the instruments used are - Turns Ratio meter (TTR) to energies the transformer from a low-voltage supply and measure the HV and LV voltages. Wheatstone

Turns Ratio / Voltage Ratio Test Test Procedure 1 (Kelvin Bridge Method Required Precaution: According to IEC 60076-1, Purpose and Instruments: Turns Ratio Test / for measurement of winding resistance): in order to reduce measurement errors due to Voltage Ratio Test are done in Transformer to find The main principle of bridge method is based on comparing an unknown resistance with a known resistance. When electric currents flowing through the arms of bridge circuit become balanced, the reading of galvanometer shows zero deflection that means at balanced condition no electric current will flow through the galvanometer.

Kelvin Bridge: Very small value of resistance

(in milliohms range) can be accurately measured

by Kelvin Bridge method whereas for higher value Wheatstone bridge method of resistance measurement is applied. In bridge method of measurement of winding resistance, the error is minimized. All other steps to be taken during transformer winding resistance measurement in these methods are similar to that of current voltage method of measurement of winding resistance of transformer.

Test Procedure 2 (current voltage method of measurement of winding resistance):

The resistance of each transformer winding is measured using DC current and recorded at a ambient temp. In this test resistance of winding is measurement by applying a small DC voltage to the winding and measuring the current through the ||www.electricalmirror.net||

For Star connected winding: the neutral brought out, the resistance shall be measured between the line and neutral terminal (i.e. R-N, Y-N, B-N) and average of three sets of reading shall be the tested value. For Star connected auto transformers the resistance of the HV side is measured between HV terminal and IV terminal, then between IV terminal and the neutral.

For Dry type transformers: the transformer shall be at rest in a constant ambient temperature for at least three hours.

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Focus : T&M Instruments Bridge Circuit.

Test Procedure 1 (Transformer Turns Ratio Meter (TTR)):

Transformer ratio test can be done by Transformer Turns Ratio (TTR) Meter. It has in built power supply, with the voltages commonly used being very low, such as 8, 10 V and 50 Hz. The HV and LV windings of one phase of a transformer (i.e. R-Y & r-n) are connected to the instrument, and the internal bridge elements are varied to produce a null indication on the detector. Values are recorded at each tap in case of tapped windings & then compared to calculated ratio at the same tap. The ratio meter gives accuracy of 0.1 per cent over a ratio range up to 1110:1. The ratio meter is used in a ‘bridge’ circuit where the voltages of the windings of the transformer under test are balanced against the voltages developed across the fixed & variable resistors of the ratio meter.

Adjustment of the calibrated variable resistor until zero deflection is obtained on the galvanometer then gives the ratio to unity of the transformer windings from the ratio of the resistors.

Bridge Circuit: A phase voltage is applied to the one of the windings by means of a bridge circuit and the ratio of induced voltage is measured at the bridge. The accuracy of the measuring

instrument is < 0.1 %.

This theoretical turn ratio is adjusted on the transformer turn ratio tested or TTR by the adjustable transformer as shown in the figure above and it should be changed until a balance occurs in the percentage error indicator. The reading on this indicator implies the deviation of measured turn ratio from expected turn ratio in percentage.

Theoretical Turns Ratio = HV winding Voltage / LV Winding Voltage; % Deviation = (Measured Turn Ratio – Expected Turns Ration) / Expected Turns Ration Out-of-tolerance, ratio test of transformer can be due to shorted turns, especially if there is an associated high excitation current. Open turns in HV winding will indicate very low exciting current and no output voltage since open turns in HV winding causes no excitation current in the winding means no flux hence no induced voltage. But open turn in LV winding causes, low fluctuating LV voltage 42

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but normal excitation current in HV winding. Hence open turns in LV winding will be indicated by normal levels of exciting current, but very low levels of unstable output voltage. The turn ratio test of transformer also detects high resistance connections in the lead circuitry or high contact resistance in tap changers by higher excitation current and a difficulty in balancing the bridge.

Disconnect all transformer terminals from line or load. Neutrals directly grounded to the grid can remain connected.

Test Procedure 2 (Voltage Ratio Testing):

This test is done to check both the transformer voltage ratio and tap changer. When “Turns Ratio meter” is not available, Voltage Ratio Test is done at various tap position by applying 3 phases LT (415V) supply on HT side of Power transformer.

In order to obtain the required accuracy it is usual to use a ratio meter rather than to energies the transformer from a low-voltage supply and measure the HV and LV voltages. At Various taps applied voltage and Resultant voltages LV side between various Phases and phases and neutral measured with precision voltmeter and noted.

With 415 V applied on high voltage side, measure the voltage between all phases on the low voltage side for every tap position. First, the tap changer of transformer is kept in the lowest position and LV terminals are kept open. Then apply 3-phase 415 V supply on HV terminals. Measure the voltages applied on each phase (Phase-Phase) on HV and induced voltages at LV terminals simultaneously.

After measuring the voltages at HV and LV terminals, the tap changer of transformer should be raised by one position and repeat test. Repeat the same for each of the tap position separately.

At other taps values will be as per the percentage raise or lower at the respective tap positions. In case of Delta/Star transformers the ratio measure between RY-rn, YB-yn and BR-bn. Being Delta/Star transformers the voltage ratio between HV winding and LV winding in each phase limb at normal tap is 33 KV OR 33x√3 = 5.196 ,11 KV / √3 11. At higher taps (i-e high voltage steps) less number of turns is in circuit than normal. Hence ratio values increase by a value equal to.5.196 + {5.196 x (no. of steps above normal) x (% rise per each tap)} 100. Similarly for lower taps than normal the ratio is equal to 5.196 - {5.196 x (no. of steps above normal) x (% rise per each tap)}100

rated voltage is applied to one winding of the transformer, all other rated voltages at no load shall be correct within one half of one percent of the nameplate readings. It also states that all tap voltages shall be correct to the nearest turn if the volts per turn exceed one half of one percent desired voltage. The ratio test verifies that these conditions are met. The IEC 60076-1 standard defines the permissible deviation of the actual to declared ratio. Principal tapping for a specified first winding pair: the lesser ±0.5% of the declared voltage ratio or 0.1 times the actual short circuit impedance. Other taps on the first winding pair and other winding pair must be agreed upon, and must be lower than the smaller of the two values stated above. Measurements are typically made by applying a known low voltage across the high voltage winding so that the induced voltage on the secondary is lower, thereby reducing hazards while performing the test. For three phase delta/wye or wyes/delta transformer, a three phase equivalency test is performed, i.e. the test is performed across corresponding single winding. Test can detect: Shorted turns or open circuits in the windings.

Incorrect winding connections, and other internal faults or defects in tap changer.

Polarity / Vector group Test

Purpose and Instruments: The vector group of

transformer is an essential property for successful parallel operation of transformers. Hence every electrical power transformer must undergo through vector group test of transformer at factory site for ensuring the customer specified vector group of transformers. Ratio meter, Volt Meter. A Ratio meter may not always be available and this is usually the case on site so that the polarity may be

Test Acceptance Criteria: Range of measured

ratio shall be equal to the calculated ratio ±0.5%.

Phase displacement is identical to approved arrangement and transformer’s nameplate. The IEEE standard (IEEE Standard 62) states that when

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Focus : T&M Instruments checked by voltmeter.

Polarity Test of Transformer

Test Procedure: The primary and secondary

windings are connected together at one point.

Connect neutral point of star connected winding with earth. Low-voltage three-phase supply (415 V) is then applied to the HV terminals. Voltage measurements are then taken between various pairs of terminals as indicated in the diagram and the readings obtained should be the phasor sum of the separate voltages of each winding under consideration.

Condition: (HV side R-Y-B-N and LV Side r-y-b-n).

R and r should be shorted. Apply 415 Volt to R-Y-B. Measure Voltage between Following Phase and Satisfy Following Condition.

Short Circuit Test

Purpose and Instruments: The value of the

short circuit impedance Z% and the load (copper) losses (I2R) are obtained. This test should be performed before the impulse test-if the later will be performed as a routine test- in order to avoid readings errors. And instruments used are Megger, Multimeter, CT, PT. Suitable Low Voltage (3-phase 415V, 50Hz) will be applied to the terminals of one winding (usually the H.V.) with the other winding short circuited with 50 sq. mm. Copper cable. (Usually the L.V.) The applied voltage is adjusted to pass the needed current in the primary/secondary. In order to simulate conditions nearest to full load, it is customary to pass 100%, 50% or at least 25% of full load current. Voltage to be increased gradually till the current in the energized winding reaches the required value (50% to 100% rated current). Measure the 3 Phase line currents at all tap position. If the tap-switch is an Off-Circuit

changing the tap.

A consistent trend in the increase or decrease of current, as the case may be, confirms the healthiness of the transformer. If transformer is equipped with a tap changer, tapping regulations are applied.

If tapping range within ±5% and rated power less than 2500 kAV, load loss guarantee refer to the principal tap only. If tapping range exceeds ±5% or rated power above 2500 kAV, it shall be stated for which tapping beside the principal tap the load losses will be guaranteed by the manufacturer. Three phase LT supply is applied on HV side of power transformer at normal tap with rated current on HV side and currents measured in all the phases on HV side and phases & neutral on LV side values noted. Readings to be taken as quickly as possible as the windings warm up and the winding resistance increases. Hence, the losses value will increase accordingly. Using appropriate instruments (conventional three wattmeter method or digital wattmeter with ammeters & voltmeters) measurements of voltage, currents and power can be recorded.

Short Circuit Test (Without using CT, PT)

To avoid CT’s and PT’s, this method can be used at current levels of 2 to 5 A and measurement of load losses is done at this condition. This measured

load loss is then extrapolated to actual load currents to obtain load losses at the operating current.

Short circuit Test without CT

performed at rated frequency. Three phase LT Voltage of 415V applied on HV side of Power transformer keeping LT open. Two voltmeters are connected to the energized winding, one is measuring the voltage mean value and the other is for the Voltage R.M.S value. Voltage applied to winding (usually to H.V. windings). It will be in a range from 90% of winding rated voltage to 110% of the same in steps, each of 5% (i.e. for a 33/11kV transformer, applied voltage values will be 29.7kV, 31.35kV, 36.3kV). Readings of watt meters, Voltmeters & Ammeters are recorded to obtain the values of V (r.m.s), Vmean, Po and Io at each voltage step. Test results are considered satisfactory if the readings of the two are equal within 3%. If it’s more than 3%, the validity of the test is subjected to agreement. Measured value of power loss is corrected according to the following formula: Pc = Pm (1+d) and D = (Vmean - Vr.m.s) / Vmean. Measure the loss in all the three phases with the help of 3 watt meter method. Total no load loss or iron loss of the trf = W1 + W2 + W3. This test should be performed before the impulse test-if the later will be performed as a routine test- in order to avoid readings errors. No Load losses to be within guaranteed values.

Continuity test: To know the continuity of windings

of the transformer. Test Instruments include Megger or Multi meter. Check Continuity of Transformer by using multi meter or by Megger between following Terminals. Test can detect Open circuit / loose Transformer

P-P

P-P

P-P

Result

HV Side

R-Y

Y-B

B-R

Zero Mega ohm or continuity

LV S;ide

r-y

y-b

b-r

Zero Mega ohm or continuity

connection of winding.

Short Circuit Test (With CT): Measured impedance to be within guaranteed value and nameplate value. Load losses to be within guaranteed values.

Test can detect Winding deformation. Deviation in nameplate value.

Open Circuit / No Load Test: In this test, the

tap-switch, the supply has to be disconnected before

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value of No-Load power (Po) & the No-Load current (Io) are measured at rated voltage & frequency. Test Instruments include Watt meters.

Ammeter, Voltmeter or Power analyser Test is

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Magnetic Current Test

Magnetizing current test of transformer locates

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Focus : T&M Instruments the defects in the magnetic core structure, shifting of windings, failure in turn to turn insulation or problem in tap changers. Equipment used are Multi meter or Mill Ammeter. These conditions change the effective reluctance of the magnetic circuit, thus affecting the electric current required to establish flux in the core. Three phases LT Voltage of 415 V applied on HV side of Power transformer and currents are to be measured with mill ammeter.

The value shall be = (1 to 2 percent of rated full load current of TC / HT KV) X Voltage Applied.

First of all keep the tap changer in the lowest position and open all IV & LV terminals. Then apply three phase 415V supply on the line terminals for three phase transformers and single phase 230V supply on single phase transformers. Measure the supply voltage and electric current in each phase. Now repeat the magnetizing current test of transformer test with keeping tap changer in normal position and repeat the test with keeping the tap at highest position.

Generally there are two similar higher readings on two outer limb phases on transformer core and one lower reading on the centre limb phase, in case of three phase transformers. An agreement to within 30 % of the measured exciting current with the previous test is usually considered satisfactory.

If the measured exciting current value is 50 times higher than the value measured during factory test, there is likelihood of a fault in the winding

which needs further analysis.

Magnetic Balance Test

Magnetic balance test of transformer is conducted only on three phase transformers to check the imbalance in the magnetic circuit. Equipment used are Multi meter or Mill Ammeter. First keep the tap changer of transformer in normal position. Now disconnect the transformer neutral from ground.

Then apply single phase 230V AC supply across one of the HV winding terminals and neutral terminal. Measure the voltage in two other HV terminals in respect of neutral terminal. Repeat the test for each of the three phases. In case of auto transformer, magnetic balance test of transformer should be repeated for IV winding 46

MARCH 2017 ||

also. There are three limbs side by side in a core of transformer. One phase winding is wound in one limb. The voltage induced in different phases depends upon the respective position of the limb in the core. The voltage induced in different phases of transformer in respect to neutral terminals given in the table below. 415V, Two phase supply is to be applied to any two phases terminals on HV side of Power transformer and voltages in other two phase combination are to be measured with LT open. Sum of the Resultant two values shall be equal to the voltage applied.

High Voltage tests on HV & LV Winding:

To checks the insulation property between Primary to earth, Secondary to earth and between Primary

Variable Voltage, Frequency Source & Auto Transformer.

The following Dielectric tests are performed in order to meet the transformer insulation strength expectations. Switching impulse test: to confirm the insulation of the transformer terminals and windings to the earthed parts and other windings, and to confirm the insulation strength in the windings and through the windings.

Lightning impulse test: to confirm the transformer insulation strength in case of a lightning hitting the connection terminals Separate source AC withstand voltage test: to confirm the insulation strength of the transformer line and neutral connection terminals and the connected windings to the earthed parts and other windings.

Induced AC voltage test: (short duration ACSD

and long duration ACLD): to confirm the insulation strength of the transformer connection terminals and the connected windings to the earthed parts and other windings, both between the phases and through the winding.

Partial discharge measurement: to confirm the â&#x20AC;&#x153;partial discharge below a determined levelâ&#x20AC;? property of the transformer insulation structure under operating conditions.

& Secondary. Test Instrument include High Voltage tester (100KV & 3KV).

LV High Voltage Test: HV high voltage test:

LV winding connected together and earthed. HV winding connected together & given Following HV Supply for 1 minute. LV high Voltage test: HV winding connected together and earthed. LV winding connected together and given Following HV Supply for 1 minute.

433V Winding = 3KV High Voltage 11KV Winding = 28KV High Voltage 22KV Winding = 50KV High Voltage 33KV Winding = 70KV High Voltage.

Di-electrical Test: To check the ability of main

insulation to earth and between winding. To checks the insulation property between Primary to earth, Secondary to earth and between Primary & Secondary. Test instruments used are 3 Phase

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Method No 1 (separate source voltage withstand test)

All the terminals of the winding under test should be connected together and the voltage should be applied. The secondary windings of bushing type current transformers should be connected together and earthed. The current should be stable during test and no surges should occur. A single phase power frequency voltage of shape approximately sinusoidal is applied for 60 seconds to the terminals of the winding under test. The test shall be performed on all the windings one by one. The test is successful if no breakdown in the dielectric of the insulation occurs during test.

During the Separate source AC withstand voltage test, the frequency of the test voltage should be equal to the transformerâ&#x20AC;&#x2122;s rated frequency or should be not less than 80% of this frequency. In this way, 60 Hz transformers can also be tested at 50 Hz. The shape of the voltage should be single phase and sinusoidal as far as possible. This test is applied to the star point (neutral point) of uniform

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insulated windings and gradual (non-uniform) insulation windings. Every point of the winding which test voltage has been applied is accepted to be tested with this voltage. The test voltage is measured with the help of a voltage divider.

The test voltage should be read from voltmeter as peak value divided by 2. Test period is 1 minute.

Dielectric Test (Separate Voltage Source withstand Test) Method No 2 (Induced source voltage withstand test)

The aim of this test is to check the insulation both between phases and between turns of the windings and also the insulation between the input terminals of the graded insulation windings and earth. During test, normally the test voltage is applied to the low voltage winding. Meanwhile HV windings should be keeping open and earthed from a common point. Since the test voltage will be much higher than the transformerâ&#x20AC;&#x2122;s rated voltage, the test frequency should not be less than twice the rated frequency value, in order to avoid over saturation of the transformer core. The test shall start with a voltage lower than 1/3 the full test voltage and it shall be quickly increased up to desired value. The test voltage can either be measured on a voltage divider connected to the HV terminal or on a voltage transformer and voltmeter which have been set together with this voltage divider at the LV side. Another method is to measure the test voltage with a peak-value measuring instrument at the measuring-tap end of the capacitor type bushing (if any). Test period which should not be less than 15 seconds. It is calculated according, Test period = 120 seconds x (Rated frequency / Test frequency). The duration of the test shall be 60 second. The test is accepted to be successful if no surges, voltage collapses or extreme increases in the current have occurred.

The test is successful if no break down occurs at

of the transformer core. The test shall start with a voltage lower than 1/3 the full test voltage and it shall be quickly increased up to desired value.

The test voltage can either be measured on a voltage divider connected to the HV terminal or on a voltage transformer and voltmeter which have been set together with this voltage divider at the LV side. Another method is to measure the test voltage with a peak-value measuring instrument at the measuring-tap end of the capacitor type bushing (if any). Test period which should not be less than 15 seconds. It is calculated according, Test period = 120 seconds x (Rated frequency / Test frequency). The duration of the test shall be 60 second. The test is accepted to be successful if no surges, voltage collapses or extreme increases in

the current have occurred. The test is successful if no breakdown occurs at full test voltage during test.

Method No 3 Lighting Impulse Test

All the dielectric tests check the insulation level of the Transformer. Impulse generator is used to produce the specified voltage impulse wave of 1.2/50 micro seconds wave. One impulse of a reduced voltage between 50 to 75% of the full test voltage and subsequent three impulses at full voltage. For a three phase transformer, impulse is carried out on all three phases in succession. The voltage is applied on each of the line terminal in succession, keeping the other terminals earthed.

The current and voltage wave shapes are recorded on the oscilloscope & any distortion in the wave shape is the criteria for failure.

full test voltage during test.

Dielectric Test (Induced Voltage Test): During

test, normally the test voltage is applied to the low voltage winding. Meanwhile HV windings should be keeping open and earthed from a common point. Since the test voltage will be much higher than the transformerâ&#x20AC;&#x2122;s rated voltage, the test frequency should not be less than twice the rated frequency value, in order to avoid over saturation ||www.electricalmirror.net||

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SPECIAL THEME : Transformers

India’s Transformer Industry - on a Threshold Of Transformation Transformers are an indispensable component

of an alternate current electrical system for electricity generation, transmission or distribution.

In addition, the demand for transformers increases proportionately with the amplification of power generation, transmission or distribution networks in the country. In India, the demand for equipment used in power sector is multiplying at a rapid rate because of social, economic and industrial development. Govt's attempt of attaining 100% electrification across the country by 2017 would contribute to the demand for power transformers.

However, power deficit across the country is likely to continue during the next decade. As of now, out of 5160 towns in India, only 35% towns have over 90% households using electricity for lighting purpose. In more than 15% of the towns, the penetration rate of electricity across households is less than 50%. Indian Power & Distribution Transformer market is forecasted to reach $2.9 billion by 2022. GoI is taking major steps to strengthen the power T&D network and has undertaken initiatives such as UDAY for financial turnaround of power discoms.

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Further, it has projected an investment of INR 146,000 Cr in power transmission sector by FY19 to strengthen the transmission network thus increasing the demand for power transformers.

The Western region accounted for the largest revenue share in the country in 2016. However, the major investment in transmission sector is expected in the Southern region, followed by the Northern and Western region. In the distribution sector, the Western region is expected to receive highest investments followed by the Southern and Northern region. India is on the verge of becoming an emerging power nation among developing economies. The availability of electricity is directly linked to the GDP growth of developing economies, India being no exception. Growth of the Indian electrical industry and its investment appeal primarily depends on govt policies. Timely capacity additions to electricity generation, T&D are necessary to improve and sustain GDP growth and reduce the electricity demand-supply gap.

The Indian Power Sector

India’s power generation of installed capacity at the end of FY2014-15 stood at 314.64 GW. Acute

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fuel shortage (both coal and natural gas), project clearances and delay in commissioning of new units, affected capacity addition plans. Although India has the 5th largest power generation capacity, globally (trailing behind China, US, Japan and Russia), a power deficit scenario has been plaguing the sector for more than a decade. India’s per capita power consumption of around 1075 kWH per annum (as at the end of FY2015-16) is significantly below the world average of 2,600 kWH and developed countries’ average of 8,000 kWH. India needs to rapidly increase its generation capacity, in order to achieve the goal set by the Ministry of Power – ‘Power for All’ by 2019. Power deficit at the end of the 11th FYP reached 3.6%, whereas peak deficit was to the tune of 4.7%. Key reasons (apart from missing out on power generation capacity addition targets) for the continued power deficit scenario in the country are: Dismal conditions and inappropriate maintenance of existing T&D equipment / infrastructure. Rampant power theft, leading to high T&D losses (at the end of FY2014-15, T&D losses were to the tune of

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20.8%) impacting financial condition of Power T&D utilities (DISCOMs & TRANSCOs). A robust and efficient power T&D infra is imperative for effective transfer of power from generation source to the consumption points / demand centres. Thus, expanding the T&D infra to transmit the power generated to consumer points across the length and breadth of the country becomes imperative.

Transformers are critical components of the Power T&D network that are used to change voltage in the power transmission and distribution process, and hence play a key role. Transformers can be broadly classified, based on the output rating as: Distribution Transformers (31.5 to 5,000 KVA), Power Transformers (5.1 to 500 MVA), Special Transformers (depending on the type of application like welding, traction, furnace, etc.)

Transformer Industry in India

The Indian transformer industry is more than 5 decades old, hence mature. Domestic manufacturers have developed capabilities to manufacture all types of equipment to meet the country’s demand for transformers up to

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800 kV and going up to 1,200 kV. The industry enjoys a good reputation in terms of quality, price, and delivery in the domestic as well as overseas markets. India’s transformer market is predominantly unorganized with many small participants catering to the smaller distribution transformer markets. However, many are slowly graduating to the medium-sized category, thus expanding the organized participants’ base. There are approximately 300+ transformer CoS in India, with an overall installed capacity of over 370,000 MVA per annum. The market is fragmented with 20 organized players including Bharat Heavy Electricals Limited (BHEL), ABB Ltd, Crompton Greaves Ltd (CGL), Areva T&D, EMCO Ltd, Bharat Bijlee Ltd (BBL), Vijai Electricals, Transformers and Rectifiers India Limited (TRIL), Voltamp Transformers Ltd, among others. In the power transformers category, companies in the high-end segment (400 kV and above) mainly include international players such as ABB Ltd, Alstom T&D (erstwhile Areva T&D India), and Siemens; and Indian manufacturers such as BHEL, CGL,

TRIL, and Toshiba Transmission & Distribution Systems India (Entity formed by acquisition of Vijai Electricals by Toshiba Corporation, Japan).

Majority of other CoS in this sector are present in the 220 kV segment in power & distribution transformers. Leading players have significant presence in both power & distribution transformer market. Apart from catering to domestic demand, India exports transformers to over 100 nations including the US, Europe, Malaysia, Singapore, Bangladesh, African countries, and Gulf countries.

India is also an importer of transformers; the major source countries include China, Germany, USA, Korea, and Japan.

Demand Outlook for Power & Distribution Transformer till 2020

India has been witnessing a significant rise in power demand for the past few decades on account of rapid growth in population, industrialization and urbanization. The govt has taken up various initiatives including Deendayal Upadhyaya Gram Jyoti Yojana (DDUGJY) for electrification of rural

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SPECIAL THEME : Transformers

pockets of India, which has spurred significant investments in the country's power sector. Notable technological upgrades are underway to reinforce the country's T&D network, which would continue to drive the demand for power and distribution transformers in India. Considering the negative impact of these technological developments on the environment, the industry has been undergoing a paradigm shift towards green technologies. As a result, transformer manufacturers in India as well as in other countries have started investing heavily towards their research and development efforts. Foreign players, especially Chinese and Korean electrical equipment manufacturers, have captured almost one fourth of Indian transformers market, mainly in EHV and UHV class power transformers, as the products offered by them are considered cheaper and technologically advanced.

According to "India Power & Distribution Transformers Market Forecast & Opportunities, 2020", the power and distribution transformers market in India is projected to grow at a CAGR of over 10% till 2020. Power transformers contribute a major portion in overall market revenues due to their higher price points. Under the 12th FYP (2012-2017), Indian government allocated US$ 200 billion for strengthening the country's power generation, transmission and distribution sector. One of the major developments underway includes the country's shift from 765 kV to 1200 kV power transmission. This, in turn, is fuelling the demand for EHV and UHV class power transformer installations throughout the

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country. India is also focusing on use of alternative energy resources like nuclear and solar energy for power generation, which is expected to further boost transformer deployments in the country in the coming years. According to the report growth of the countryâ&#x20AC;&#x2122;s power T&D sector remained sluggish during 10th &11th FYP due to inadequate investments allocated by the Indian govt. However, under the 12th FYP, the GoI is focused towards expansion of the countryâ&#x20AC;&#x2122;s T&D network with significantly higher investments than previous 5 year plans, which is expected to result in robust growth of the industry over the next 5 years. Upcoming govt projects like Green Energy Corridor for power generation from renewable sources would further add to the overall power and distribution transformer installations in the country.

India has also entered into a technological collaboration with Germany under which Germany would extend its technical assistance for upgrading Indiaâ&#x20AC;&#x2122;s existing power grid and facilitate flow of renewable energy through the grid. Other initiatives like RAPDRP are aimed at providing basic power infrastructure to rural inhabitants and households in the country, thereby buoying the demand for power & distribution transformers in India. The report also highlights the increasing penetration of Chinese transformer manufacturers in the Indian market, signalling higher competition ahead for domestic manufacturers. Two major Chinese companies, TBEA and Baoding TianweiBaobian, have already

set up their transformer manufacturing units in Gujarat, while other Chinese players are showing interest in entering India through joint ventures and collaborations. Indian companies, on the contrary, are more focused towards exports as they earn higher profit margins on transformer exports to countries like the US, South Africa, Cyprus and Iraq. To reduce their dependence on overseas laboratories for testing extra high voltage transformers, Indian players are also focusing on establishing their in-house testing facilities, mainly for UHV class transformers.

Power transformers contribute a major portion in overall market revenues due to their higher price points. Under the 12th five year plan (2012-2017), Indian government allocated US$ 200 billion for strengthening the country's power generation, transmission and distribution sector. Power requirement is the keydriver for the transformers market and due to increasing electrification ratio in India, the demand is on the rise. In addition, load growth combined with high T&D losses are likely to create the need for more substations, thereby increasing the demand for power and distribution transformers. Realizing the importance of private participation in the power sector, the Indian Government is strengthening its policies to encourage private investments.

The Electricity Act 2003 caused the compulsory unbundling of the SEBs) to improve their operational efficiencies, thus creating new market demand for better transmission equipments. New analysis from Frost & Sullivan -- Indian Power and

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Distribution Transformers Market-- reveals that revenues in this industry totalled $1.04 billion in 2005 and is likely to reach $5.31billion in 2012.

Govt’s emphasis on the T&D sector reforms and investments are showing signs of fruition, thus creating a phenomenal growth opportunity for the Indian transformer market.

Due to rapid economic development and government's target of 'power for all by 2012,'the Indian power sector will need to replicate what has been achieved during the last 50 years in the next 10 years. Growing presence of global participants in the power and distribution transformers market is a cause for concern for local manufacturers. International manufacturers have expertise in segments such as EHV power transformers and unitized substation technologies.

Moreover, low investment in transformer R&D in India pose a challenge to domestic participants, who eventually tie-up with multinational giants for high-end technologies. The global price hike in transformer raw materials such as copper, aluminium, and oil resulted in the increase in transformer prices in India. Also, shortage of cold rolled grain oriented steel (CRGO) is further escalating the price of this essential 'transformer core' material. With growing demand and price correspondingly rising, manufacturers are finding it difficult to maintain margins in the long term, thereby transferring burden of increased costs to end users. The regulatory structure of the power sector has faced some uncertainties due to the reluctance and failure of certain states to put the regulations into practice. Furthermore, utilities are confronting financial problems because of high T&D losses, thus increasing their debt.

Despite these setbacks, the power sector in India is likely to remain buoyant. Reforms in the sector and the enlargement of the power distribution network under the APDRP is driving the growth and strengthening of sub-transmission lines. In addition, the increase in transmission grid reliability will result in heightened demand for power transformers.

Other than the central and state utilities plans for power capacity addition, private sector investment is also expected to have a profound influence on the development of the power industry.

Also, ageing equipment is creating potential for a booming replacement market and this demand will be sustained by the growth in industrial demand. The demands driving the transformer market are dependent on urbanization and infrastructural developments within the country.

With India leapfrogging into the future, this

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market is less likely to hit any speed bumps along the way.

Indian Transformer Market Size

The Transformer market in India can be pegged at more than INR 12,000 Crores. Power Transformers contribute 45% of the total market and distribution transformers, 55%. Over the last 2 years, the market has grown at a very moderate rate at less than 4 percent, due to the slowdown of power generation capacity addition and T&D infra expansion. Anticipating the huge domestic (due to a power deficit scenario, requirement of power sector expansion) and overseas demand, the transformer industry in India has more than doubled its manufacturing capacity over the last 5 years. Transformer manufacturing capacity in India stands at ~370 GVA with capacity utilization rates hovering around 60-70 percent on an average over the last 5 years. Transformer overcapacity in the Indian market has led to immense pricing pressure scenario severely impacting the profitability of the market players.

India’s huge power shortage, need to ramp up power T&D infrastructure, economic slowdown of developed markets like Europe and North America and excess transformer manufacturing capacity in China has resulted in India being an attractive destination for transformer companies globally to tap the Indian market opportunity.

Anticipating this, many foreign players are already in the process of setting up base in India. Over the last 18-30 months, new players have entered the market either through acquisitions or through setting up of facilities within India. A few notable Our Product Range Includes: 1 2 3 4 5 6 7

Distribution Transformers Servo Voltage Stabilizers Ultra Isolation Transformers Induction Furnace Transformers Special Purpose Transformers Distribution Transformer with OLTC Dry Type Transformer (VPI)

examples are: Canadian company, Hammond Power Solutions Inc. had acquired 70% equity stake in the Hyderabad based transformer supplier Pan-Electro Technic Enterprises Pvt. Ltd in Feb’ 2012. Chinese manufacturer, TBEA has set up transformer manufacturing unit in Gujarat in order to qualify for the bids from PGCIL.

Market Drivers

Power Generation Capacity augmentation and Power T&D infra expansion to be in-line with Power generation capacity addition. According to the 12th plan, INR 1200K-1300K Crores likely to be invested in the power sector. This spending on the power sector is expected to be equally distributed between generation and T&D. Spending on Power T&D infra is expected to boost demand for transformers. RGGVY scheme to improve rural electricity infrastructure and rural household electrification. The electrification drive is expected to provide impetus to demand for distribution transformers. Increasing focus on Rural Electrification APDRP 1-2 in order to minimize AT&C losses at the distribution level and improve the financial health of the SEBs. Industrial sector growth. Replacement of ageing equipment.

These reforms are expected to significantly affect demand for transformers over the next 4 to 5 years.

Market Challenges

Inadequate supply of prime quality Cold Rolled Grain Oriented (CRGO) steel is the biggest challenge faced by transformer manufacturers in the country. CRGO requirement is completely met through imports; it is in fact challenging to assess the true quality of the material that is used

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SPECIAL THEME : Transformers

by the transformer manufacturers in India. India needs 2.5 lakh tons of CRGO every year and an appalling 70 % of this is scrap grade material.

Failure rate of Transformers – High failure rate of distribution transformers, is a big concern for the transformer industry in India. The average operational life of a transformer is between 25-30 years; however, transformers are known to be recalled for repair in as early as three years.

The failure rate of distribution transformers in India is estimated at 10-15% (in stark contrast to the less than 2% failure rate in developing countries). This is due to the low entry barriers in the distribution transformer market leading to unorganized players entering the market, and competing on the price factor. SEBs historically follow a L1 vendor selection criteria, which has led to proliferation of many small players, that compromise on the quality of transformers manufactured.

Financial Condition of SEBs - SEBs have been facing losses due to the supply of subsidized

power to agricultural farmers, theft of power, and inefficient T&D infrastructure. This has restricted private investment in the power T&D sector, thereby reducing the quality of service from SEBs. This, in turn, is affecting the capacity building program and transmission of power.

Lack of testing facilities – The growth in testing infrastructure has not kept pace with that of production, both, quantitatively and qualitatively.

Testing infrastructure available at India's premier agency, the Central Power Research Institute (CPRI) is proving short of demand. Manufacturers of large power transformers at times need to send their equipment for testing to overseas facilities like Korea Electrotechnology Research Institute (KERI) and KEMA which is expensive.

Apart from this, huge logistical costs and lead times are also involved.

Way Forward

The Indian power and distribution transformer markets are highly dependent on investments planned by the Government of India for the

T&D segment and reform programmes like the RAPDRP and RGGVY. These programmes, when fully implemented as scheduled, are expected to drive the demand for both power and distribution transformers. The GoI currently plans to strengthen transmission lines and create a National Grid interconnecting the 5 regions (northern, southern, eastern, western, northeastern) through the creation of 'Transmission Super Highways;' this is expected to drive the demand for higher-rated power transformers. With T&D CoS actively striving to reduce AT&C losses, the demand for energy-efficient transformers would get a boost. With huge investments proposed across sectors such as power, infra, etc., the transformers market in India is slated for strong growth. The excess capacity in the Transformer industry in India, and entry of new players is further expected to increase market competitiveness. Market consolidation over the next few years is inevitable.

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GUEST ARTICLE

Power quality (PQ) solutions for efficient use of electrical power.

Introduction :

Electrical power is a major cost in any industrial operation. As much as electricity is a basic necessity of running any industrial plant- big or small, it is also an input that impacts quality and productivity of the manufactured product in the Industry.

Utilities that supply electrical power to these industries, have a different set of issues. Poor power quality affects the amount of power that can be transmitted on a long EHV/HV as an example.

An example of good power quality means utility can add more customers (loads) with minimal infrastructure, lesser T&D losses-and higher reliability. All of these are important in maximizing the usage of generated power which is always short in supply as compared to the ever growing demand for electricity in India & many countries.

In recent years relatively larger attention has been given to power quality due to a deeper understanding of the economic consequences of poor power quality. These consequences are mainly • Increased operational costs in the form of penalty for low power factor (PF), increased maximum demand (MD-KVA) and higher losses that adds to the cost of power • Loss of productivity due to harmonic pollution, voltage fluctuations, over loading, and equipment break downs • Total harmonic distortion (THD) penalty which also increases cost of power

Defining power quality

In a system where AC power is purchased by an industry, power quality is an ideal state where • The wave form is pure sinusoidal (Zero distortion- THD) • No frequency deviations beyond allowed limits (refer specifications from organizations such as CEA, SEBs, REC etc.)

• Voltage variation well within tolerance range as stipulated in the applicable standards, • Voltage dips(less than 10 % lower than the rated voltage) & sags, • Power factor (PF) (KW/KVA) is close to 1 (unity) where KVA = KW meaning no reactive power drawl from the utility.

• Unbalance loading between phases in a 3 phase is nil or low (< 10 % normally doesn’t create problems) 54

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When an industrial unit does not meet one or more of the above conditions, a power quality problem may exist in the network and could be manifested in one are more of the following ways: Higher expenditure on electricity. (This can vary a little from place to place depending on the local tariff structure and penalty policy for PF or THD or both, outside specified limits defined by applicable standards).

Lower utilization of electrical machinery (asset) due to over loading of equipment arising out of low PF, high THD and low voltage to name a few common causes. Some argue that in the design specification of this electrical machinery, there is factor of safety to care of overloading. However when overloading happens due to poor power quality then it becomes the new continuous loads and the factor of safety is in reality not there at all.

This leads to pre-mature equipment failure, sometimes seemingly unexplained failures, which in reality may be due to power quality issues.

At a lower level of poor power quality, equipment may not fail, but it may Malfunction leading to process quality issues and may even disturb the process flow.

With an unsolved power quality issue, capacity expansion of any shop floor would automatically mean new capex and a need for additional equipment.

Solutions to power quality problems in industries.

Step 1: Starter….

To be able to find an efficient and cost effective solution for the power quality, it is important to study the various aspects related to power quality in the network it is important to assess and identify the cause of poor power quality and quantify the cause with proper data collection. A joint design review between user and suppliers also helps to understand the overall system as well as, expansion plans in near future, history of equipment performance and data of electrical disturbances recorded if any are important parameters that should be considered in this face. it is also important to carry out simple power system study (harmonic analysis at different time zones, various loading conditions and at critical nodal points). This phase is the most crucial stage that is ignored or sometimes done partially only.

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Consequence of improper ground work can lead to either under-designed or over-specified equipment -both of which are not desirable.

Once the power quality problem is properly defined, understood and well documented, then we can find an ideal techno-commercial solution for solving the problem.w Step 2:

Understand what solutions are available and how to choose the best fit for a given issue.

Power quality solutions have probably the highest band width of products/solutions to choose from and there are different technologies that are applied at different voltages like EHV/HV, MV& LV. Tables enclosed below give an indication of different power quality issues that we may come across at various voltage levels. Also given below are a range of solutions that has been applied at different voltage levels for various industry applications/type.

The evolution of these PQ solutions in India began with the use of a simple fixed shunt capacitor banks in the year 2000 in only LV & MV applications and in HV up to 132 kV. In LV networks industries were using APFC and for MV only few industries tried out dynamic power quality solutions using SVC (fixed capacitors& thyristor controlled reactors).

Most fast dynamic PQ solutions in LV, MV and HV were imported.

Post year 2000, key components required in PQ solutions for the HV/EHV were available locally, while at the same time, we could see the capacitor industry getting into fast dynamic PQ Solutions for LV & MV Today PQ solutions for LV, MV and HV/EHV across all types of industries are available locally. A lot of these solutions are exported to many countries as well. However imports in power electronic based switched capacitor/compensator solutions & filters, DC Capacitors etc continue as well.

Practical issues that come up in implementation of power quality solutions.

As can be seen in tables above at any voltage/ application there are numerous power quality issues and multiple choice of solutions that can be used. So a good amount of knowledge has to be gathered to do a proper application check and decide the best fit solution.

Generally it is felt that a simple fixed shunt capacitor ||www.electricalmirror.net||

Power Quality Issues in EHV/ HV applications Power quality issue

PQ Solutions Shunt Capacitors

Shunt Filters

Series Capacitors

SVC

DC filters

Voltage drop & High losses Limited Power transfer capacity Low varying Power factor and high swings in voltages Low Power factor and Harmonic distortion DC smoothening (HVDC)

Power Quality Issues in MV applications

MV Power quality issue

Product /Solution Outdoor/Indoor

Outdoor/Indoor

Fixed Shunt Capacitors Fixed Shunt Filters

Outdoor mechanically Switched

Real time correction with Thyristor or IGBT

Real time correction with Thyristor or IGBT

Mechanically switched

Pole mounted capacitors.

MV SVC (Fixed Capacitor + Thyristor controlled reactor)

Thyristor Switched capacitors /IGBT based STATCON or Active filters connected thro step up trafo

"MV Switched capacitors (Metal enclosed)"

Voltage drop & High losses, Low PF (Outdoor/Indoor) Voltage drop & high losses (remote lines no s/s), Long lines in distribution utilities Low varying power factor with Flicker & harmonics Low Power factor and Harmonic distortion Rapid Fluctuating Power factor, Indoor installations, Safety,High pollution levels.

Power Quality Issues in LV applications

LV Power quality issue

Product /Solution Fixed capacitor

Fixed Filter bank

Switched Capacitor for stepped compensation

Realtime, Dynamic, Smooth & Stepless compensation

Shunt Capacitors

Shunt Filters

APFC (contactor switched capacitors)

STATCON & Detuned or tuned filter capacitors

TSC (Thyristor switched capacitors)

Active filters with or without fixed capacitors

Low Power factor (not varying much + limited harmonics) Low Power factor (slow to medium fluctuations) Low Power factor and Fast changing loads + Limited harmonics Low Power factor (rapid fluctuating) and Harmonic distortion Unbalance in Voltages, highly fluctuating power factor combined with Harmonic distortion.

Very high harmonic distortion, unbalance , History of increased equipment failures, high nuetral currents

||www.electricalmirror.net||

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GUEST ARTICLE

bank is the cheapest and easy to operate power quality solution.

While this is true for many applications, it also not the best solution when we are dealing with multiple PQ issues and fast varying loads. These may require fast varying solutions also referred as dynamic PQ solutions (like Active filters, STATCON, SVC, TSC etc.) which may be relatively more expensive but technically proven to be more precise solutions.

Baring a few big industry houses and large utilities, a considerable section of small, medium & many more large industries are not realizing the full benefits of various power quality solutions that are mentioned above. Avoiding penalty is the only easily visible saving that many look at. The PQ solutions add much more value (across utility & industry) by way of better utilization of assets, lower operating costs due to lesser losses, maintenance & repairs.

There are some impediments also that need a mention. Some users have faced problems in not getting the required results expected from dynamic PQ solutions. The problems are mainly attributable to lack of a comprehensive design review & relevant data that needs to be properly communicated or understood by both user and supplier. The ratings of the PQ solution also matters a lot. In trying to push down the costs the rating of a solution & its sizing should never be compromised. Taking environmental conditions into design inputs such as pollution severity, temperature levels, humidity,

altitude, seismic zones are all crucial.

If there really is a budget constraint then alternate economical solutions can be explored with a judicious hybrid of fixed or passive filters with power electronic switching solutions. A possibility for tradeoff of cost vs features or performance always exists. Many industrial users have tried various PQ solutions and have decided on what suits them the most. There has to be openness, transparency and trust in deciding the best fit PQ solution.

Conclusion,

It must be said that while some users (both in utility & industrial segments) have been using and are satisfied with proven, traditional, most economical fixed shunt compensation, there are also many good examples of users who have tried and benefited from other PQ solutions (using techniques like SVC, RTPFC (TSC), STATCON, Active filters, Hybrid solutions (combining fixed and dynamic compensators. All these PQ solutions are relatively expensive when compared to fixed compensation systems. However when the larger picture of overall benefits is considered (direct savings & long term gains from better asset utilization), then the ROI can be seen in a short period of time.

On supplier side perspective, it is also a responsibility that we give the most optimal cost-effective solution that a particular PQ problem demands. While some users over simplify the need for power quality improvement and its specifications, there are cases

of over-design & needless complex solutions from suppliers side which in the long run doesnâ&#x20AC;&#x2122;t end up winning the confidence of a user. All solutions have a common goal to ensure electrical power reaches as close as possible to â&#x20AC;&#x153;Best Power qualityâ&#x20AC;? and highest energy efficiency.

PQ solutions are still underutilized at large in India and both power suppliers (utilities) and power users (users across all market segments whether it is industries, Infrastructure, transport, data centers etc.) are continuous evolving.

A unit of electrical energy saved is equal to two units of energy generated What matters is not how much power is generated in various power stations but how much of it is reaching the loads that makes use of this power.

Good power quality ensures lowest cost of operations and highest returns for power suppliers and users.

Shylendra Kumar

Vice President, Capacitors & Filters, ABB India Limited.

net

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ON SITE MEASUREMENT ON POWER TRANSFORMERS USING THE WHOLE TESTING TOOLBOX Markus PĂźtter, Michael KrĂźger; Christian Enk, Inho Hong, Omicron Electronics Gmbh

Abstract: Power transformers are critical, capital-intensive assets for utilities and industry. Transformers are extremely reliable; however, many of the transformers in use today have already exceeded their design life. Today transformers are not automatically replaced, if they have reached the end of their life span, but left in service as long as possible. In contradiction to the past many power transformers are operated nowadays at or above rated power. With advancing age of power transformers, a regular check of the operative condition becomes more and more important. The Dissolved Gas Analysis (DGA) is a proven and meaningful method such that if increased proportions of H2 and hydrocarbon gases are found in the oil, the fault must be located as soon as possible. In order to find out the reason for high gas rates, further tests have to be performed. Common methods are: winding resistance measurement (static), On-Load Tap Changer (OLTC) test (dynamic resistance test), turns ratio and excitation current measurement, measurement of the leakage reactance and of the frequency response of stray losses (FRSL), the measurement of the transfer function (FRA), capacitance and dissipation factor measurement, the measurement of Partial Discharges (PD) and dielectric response measurement with PDC and FDS.

1 INTRODUCTION

Several tests can be performed to determine the condition of power transformers. Routine tests are for example oil analysis so called DGA analysis.

Also some electrical values like winding and insulation resistance, no load current or capacitance and dissipation factor (DF) at mains frequencies were measured on site periodically. Online monitoring systems were introduced to gather current data about e.g. the voltage, current or the temperature. Such systems can help to recognize rapid changes of the transformer condition very early. Not every test can be performed online, but for example online monitoring systems for the oil, tap changer, cooling system or the bushings are already available. Very often a set of diagnostic measurement are needed to identify a specific fault. The most common electrical diagnostic measurement methods are listed in table 1. (table 1).

Table 1: Most common electrical diagnostic measurement methods

2 DIAGNOSITC MEASURMENT METHODS

2.1 Dielectric Response Measurement Increase of water in oil-paper insulations goes hand in hand with transformer aging, it decreases the dielectric withstand strength, accelerates cellulose 58

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decomposition and causes the emission of bubbles at high temperatures.

State of the art for moisture measurements are equilibrium diagrams where one tries to derive the moisture in the solid insulation (paper, pressboard) from moisture in oil. This method fails for several reasons [1]. To assess the insulation's water content some dielectric diagnostic methods were widely discussed and occasional used during the last decade. The multilayer insulation of common power transformers consists of oil and paper and therefore shows polarization and conductivity effects.

Dielectric diagnostic methods work in a range dominated by interfacial polarization at the boarders between cellulose and oil, cellulose conductivity and oil conductivity. Moisture influences these phenomena. Temperature and the insulation construction have a strong impact too. In [2] a comparison of the mentioned methods was analysed. FDS and PDC methods give rather reliable results and reflect also the influence of the temperature and the geometry by using an X-Y model. The results of the PDC measurement can be transformed from the time domain into the frequency domain [3], [4] and [5]. Although the results of PDC and FDS methods are comparable and can be transformed from the time domain into the frequency domain and vice versa, both methods have advantages and disadvantages. If the FDS shall be used down to 100uHz, a measuring time of up to twelve hours is needed for one measurement e.g. the insulation gap between HV and LV winding. If also other insulation gaps e.g. HV winding to tank or LV to TV winding shall be measured, even more time is necessary. The PDC measurement needs much less time but is limited to frequencies up to about 1Hz. A new approach combines both methods [6]. The FDS measurement is replaced by the PDC method in the low frequency range and the results are transformed into the frequency domain, whereas the FDS is used for higher frequencies, which can be done rather quickly. Two input channels for simultaneous measurement of two insulation gaps make it even faster.

New model curves for aged oil-pressboard insulation, an outcome of a research project at the University of Stuttgart make the results for aged transformers much more reliable compared to the standard model curves for new oil-pressboard insulation which were used up to date.

2.2 Winding Resistance Measurement and OLTC Test Winding resistances are measured in the field to check for loose connections, broken strands and high contact resistance in tap changers. Additionally, the dynamic resistance measurement enables an analysis of the transient switching operation of the diverter switch. In most cases, the tap changer consists in most cases of two units. The first unit is the tap selector, which is located inside the transformer tank and switches to the next higher or lower tap without carrying current. The second unit is the diverter switch, which switches without any interruption from one tap to the next while carrying load current. The commutation resistances R or inductors L limit the short circuit current between the taps which could otherwise become very high due to the switching of the diverter contacts without during the period, where both taps are connected. The switching process between two taps takes approximately 40-80 milliseconds.

Dynamic Behavior of the Diverter Switch ||www.electricalmirror.net||

In the past only the static behavior of the contact resistances has been taken into account in maintenance testing. With a dynamic resistance measurement, the dynamic behavior of the diverter switch can be analysed (figure 1) [8]

Figure 2: TanDelta = f(T) at 50Hz

Figure 1: Dynamic resistance measurement

For the dynamic resistance measurement, the test current should be as low as possible otherwise short interruptions or bouncing of the diverter switch contacts cannot be detected. In this case, the initiated arc has the effect of shortening the open contacts internally. Comparison to "fingerprint" results, which were taken in a known (good) condition and to the other phases, allows for an efficient analysis. A peak detector measures the peak of the ripple (delta I) and the slope (di/dt) of the measured current, as these are important criteria for correct switching. If the switching process is interrupted, even for less than 500us, the ripple and the slope of the current change dramatically.

2.3

Frequency Response of Stray Losses (FRSL)

The frequency response measurement of stray losses is a tool to determine short circuits of parallel strands. The resistive part of the short circuit impedance is measured over a frequency range from 15Hz up to 400Hz. The resistance curves of the three phases are compared. The 15Hz values are very close to the DC values of the primary winding resistance plus the resistance of the secondary winding multiplied by the square of the ratio. If the curve of one phase is more than 2-3% different from the other phases a short circuit fault between parallel strands can be the reason for this behavior. Local overheating can cause dangerous breakdowns this behavior.

Local overheating can cause dangerous breakdowns

Figure 3: TanDelta = f(f) at 30°C

Limits for the Dissipation Factor

In the existing standards limits are given for 50/60Hz only. The measurement of the dissipation factor at other frequencies should be also included in the standards. Low frequency results (e.g. 15Hz) allow for a very sensitive moisture assessment, measurements at high frequencies (e.g. 400Hz) allow a very sensitive detection of contact problems at the measuring tap or at the layer connections. Also high resistive partial break downs between grading layers can be detected. Table 2 shows indicative limits for new and aged bushings at different frequencies [8]. All tests were done with test voltages of 2kV. The values in this table were extracted out of more than 2000 different measurements. They were calculated as average values plus two times the standard deviation. That means that 95% of the results were below these values [10].

2.4 Capacitance and Dissipation Factor (tan ) Measurement

In the past, the dissipation or power factor was measured at line frequency only. With the described test system it is now possible to make these insulation measurements in a wide frequency range. Beside the possibility to apply frequency sweeps, measurements can be made at frequencies different from the line frequency and their harmonics. With this principle, measurements are possible also in the presence of high electromagnetic interference in high voltage substations.

Dissipation Factor (DF)Measurements on High-voltage Bushings

Bushings with high moisture in the insulation show increased 50/60Hz tan values particularly at higher temperatures. Figure 2 shows the DF of OIP bushings at 50Hz for different water contents as f(T) [9], figure 3 the DF as function f(f) of the frequency at ambient temperature. ||www.electricalmirror.net||

Table 2: Indicative limits for bushings [8],[10] 2.5 Sweep Frequency Response Analysis (SFRA) Sweep Frequency Response Analysis (SFRA) has turned out to be a powerful, non-destructive and sensitive method to evaluate the mechanical integrity of core, windings and clamping structures within power transformers by measuring the electrical transfer functions over a wide frequency range.

This is usually done by injecting a low voltage signal of variable frequency into one terminal of a transformers winding and measuring the response ELECTRICAL MIR ROR

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signal on another terminal. This is performed on all accessible windings following according guidelines. The comparison of input and output signals generates a frequency response which can be compared to reference data, to other phases, or to sister transformers (figure 4). The core-andwinding-assembly of power transformers can be seen as a complex electrical network of resistances, self- and mutual inductances, ground capacitances and series capacitances. The frequency response of such a network is unique and, therefore, it can be considered as a fingerprint.

Geometrical changes within and between the windings change mainly the

within tolerable limits (table3) which indicates that no cellulose is involved.

Normal <

Abnormal>

ppm

ppm

Hydrogen H2

150

1,000

4,700 PD.Arcing

Methane CH4

25

80

16,000 Sparking

Ethane C2H6

10

35

6,000 Local overheating

Ethylene C2H4

20

150

16,000 Severe overheating

Acetylene C2H2 Carbon monoxide CO Carbon dioxide CO2

Result ppm Interpretation

15

70

500

1,000

2,700 Arcing 1,100 Overheating of paper

10,000

15,000

8,700 Overheating of paper

10000Nitrogene N2

100000

n.a

64,000

35000

n.a

19,000

300

500

58,400

2000Oxygene O2 Total combustible gas

Table3: DGA on the 220 kV transformer

Figure 4: Principle operation of SFRA

capacitor elements of the network and cause deviations in its frequency response. Differences between an FRA fingerprint and the result of an actual measurement are an indication of electrical variations of the components of the equivalent circuit diagram. Different failure modes affect different parts of the frequency range and can usually be discerned from each other.

Practical experiences as well as scientific investigations show that currently no other diagnostic test method can deliver such a wide range of reliable information about the mechanical status of a transformer's active part.

2.6

Partial Discharge Measurement

Partial discharge (PD) measurement is a worldwide accepted tool for quality control of high voltage apparatus. Outside screened laboratories PD signals are very often superposed by noise pulses, a fact that makes a PD data analysis more difficult for both human experts and software expert systems. Therefore the handling of disturbances is one of the main tasks when measuring PD. A new field of evaluation methods is opened by fully synchronous multichannel PD acquisition in order to gain more reliable measuring results combined with effective noise suppression. A technical overview of the system is given in [11].

Being able to perform synchronous multi-channel PD measurements, the Three-Phase-Amplitude-Ratio-Diagram (3PARD) was introduced as a new powerful analysis tool to distinguish between different PD sources and noise pulses when measuring high voltage equipment such as power transformers, rotating machines and cable systems. Responses of the PD are received simultaneously at three different positions of the measurement circuit. The amplitudes of three PD channels are geometrically added like vectors in a star diagram, where the three axes are corresponding to the three channels.

A PD source corresponds normally to an amplitude ratio of the three responses which is defined by the coupling of the PD signal into the three channels. Noise is normally more or less received with similar amplitude responses from the three channels. The addition of the three similar noise signals gives a position close to the star point of the 3PARD.

3

CASE STUDIES

3.1 Overheating of a 220 kV Transformer A transformer for 220kV / 50MVA showed strongly increased values of Methane, Ethane, Ethylene and Acetylene. Carbon Monoxide and Carbon Dioxide were 60

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First the high voltage winding resistance was measured on all taps. The star point of the transformer was not accessible, so the measurement was made phase to phase. The values were first not really stable on some taps on the U-V measurement. The test was repeated after some movements of the tap changer. The repeated test didn't indicate any fault. By moving the tap changer contacts, the contact surface was cleaned. The problem could be found by measuring the low voltage windings. Phase 2w showed an increase of the resistance value of 12% compared to the other phases (figure 5).

The inner connection between the bushing and the conductor had a rather high contact resistance, most probably by a high short circuit current close to the transformer in the past.

Figure 5: Increased internal contact resistance on 2w

3.2 High dielectric losses on a 123kV RBP bushing

One bushing on a 123kV transformer showed extreme high Tan Delta values particularly at low frequencies. The bushing was exchanged and then opened (figure 6). The reason for the fault was a crack in the metal hood of the bushing. So water could come into the porcelain and caused creeping discharges on the resin surface.

Figure 6: Surface of the opened active part

||www.electricalmirror.net||

3.3 FRA on a damaged 110kV transformer

A transformer for 110kV/30MVA showed unbalanced voltages on the LV windings after a short circuit close to the transformer. The FRA measurement results are shown in figure 7. The phases U and W are very similar whereas Phase V was totally different. The transformer was transported to a workshop and analysed. The short circuit current on the LV side caused an interruption of one of the two parallel windings of the phase V. The winding was interrupted at one end (figure 8). The whole clamping structure with the press rings and the spacers was broken. It was decided Figure 7: SFRA on the 110kV transformer to recycle the transformer.

The transformer was excited from the low voltage side by a small hydro generator. With a step-up transformer the 6kV output voltage was transformed to the rated secondary voltage of the test object of 21kV. It can be seen in figure 10 that the three different clusters in the 3PARD diagram are generated by three different PD sources: statistical noise, pulse disturbances and inner partial discharges. The interference noise shown in the right hand picture of figure 10 has disappeared in the other pictures. This way PD sources can be separated from each other and from noise.

4 SUMMARY

Figure 10: 3PARD filtering

With advancing age transformers require regular checks of the operating conditions. Measurement of the water content in oil-paper insulation is a helpful tool for making an assessment of the ageing of the cellulose. The analysis of the gas in oil is a well-proven method of analysis but must be complemented by efforts to locate any faults indicated by excess hydrocarbon gases in the oil. This way important maintenance can be performed in time to avoid a sudden total failure. The fault location can be successfully performed using modern type test equipment for resistance, winding ratio, short circuit impedance, C, tan , FRA and PD measurements.

5 REFERENCES Figure 8: Interrupted winding

3.4 Partial Discharge Measurement on a Repaired Transformer

Figure 9 shows a PD measurement with four simultaneously measuring channels which are connected to the three HV bushings and the star point.

Figure 9: PD measurement on a 110kV transformer ||www.electricalmirror.net||

[1] M. Koch “Improved Determination of Moisture in Oil-Paper-Insulations

by Specialised Moisture Equilibrium Charts” Proceedings of the XIVth International Symposium on High Voltage Engineering, p. 508, Beijing, China, 2005 [2] M. Koch, K. Feser "Reliability and Influences on Dielectric Diagnostic Methods to Evaluate the Ageing State of Oil-Paper-Insulations" APTADM Wroclaw 2004 [3] D. Giselbrecht, T. Leibfried "Modelling of Oil-Paper Insulation Layers in the Frequency Domain with Cole-Cole functions" ISEI (IEEE) Toronto 06/2006 [4] V. Der Houhanessian “Measurement and Analysis of Dielectric Response in Oil-Paper Insulation Systems”. Ph. D. dissertation, ETH No. 12832, Zurich, 1998 [5] A.A. Shayegani, H. Borsi, E. Gockenbach, H. Mohseni "Time Optimization of Dielectric Response Measurements" Nordic Insulation Symposium, Trondheim, Norway, June 2005 [6] H. Borsi, E. Gockenbach, M. Krüger "Method and apparatus for measuring a dielectric response of an electrical insulating system" US2006279292 [7] Hensler, Th., Kaufmann, R., Klapper, U., Krüger, M., Schreiner: S., 2003, "Portable testingdevice", US Patent 6608493 ELECTRICAL MIR ROR

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[8] "Guide for Transformer Maintenance", Cigre Brochure 445, February 2011, ISBN: 978-2-85873134-3 [9] ABB, "Dissipation factor over the main insulation on high voltage bushings", product information, ABB 2002 [10] M.Krüger, A. Kraetge, M. Koch, K. Rethmeier et al. „New Diagnostic Tools for High Voltage Bushings“, Cigre VI Workspot, Foz do Iguacu, April 2010 [11] K. Rethmeier, M. Krüger, A. Kraetge, R. Plath, W. Koltunowicz, A. Obralic, W. Kalkner, Experiences in On-site Partial Discharge Measurements and Prospects for PD Monitoring, CMD Beijing 2008 [12] K. Rethmeier, A. Obralic, A. Kraetge, M. Krüger, W. Kalkner , R. Plath. "Improved Noise Suppression by real-time pulse-waveform analysis of PD pulses and pulse-shaped disturbances", International Symposium on High Voltage on High Voltage Engineering (ISH), Cape Town, August 2009

Conclusion This article highlights the importance and the effect of residual magnetism. It should also increase the awareness of the associated risks with re-energizing transformers after an outage.

Within the last few years, the first testing devices such as OMICRON's CPC 100 have been developed which allow areliable on-site demagnetization of transformerswithout any major additional effort. Demagnetized transformer cores minimize the risk for personnel and equipment during installation. The sweep frequency response analysis measurement method is now described in the International Electrotechnical Commission’s IEC 60076-18 standard: “Power transformers - Part 18: Measurement of frequency response” and the IEEE Standard Association’s IEEE C57.149: “Application and Interpretation of Frequency Response Analysis for Oil-Immersed Transformers” and has becomeincreasingly accepted as diagnostic method. To gain reliable and reproducible measurement results, we recommenddemagnetizing the transformer core beforeperforming SFRA measurements.

Using OMICRON's CPC 100 test instrument together with Primary Test Manager and the CP SB1 switchbox, the test set up for demagnetization is simpleand requires no rewiring. The residual magnetism of transformers can then automatically be reduced almost to zero. This counteracts the effects of high inrush currents and increases the reliability of diagnostic testing.

Fig.: OMICRON's CPC 100 testing solution with the CP SB1 switchbox (J. Dickert, R. Luxenburger, P. Schegner) [3] "Mitigation of Inrush Currents in Network Transformers by Reducing the Residual Flux with an Ultra-Low-Frequency Power" (Baris Kovan, Francisco de León, Dariusz Czarkowski, Zivan Zabar und Leo Birenbaum) [4] "Remanent Flux Measurement and Optimal Energization Instant Determination of Power Transformer" (GoranPetrović, TomislavKilić, StankoMilun)

Formulas:

Literature:

[1] "On the ringdown transient on transformers" (N.) Chiesa, A. Avendano, H. K. Høidalen, B. A. Mork, D. Ishchenko and A. P. Kunze) [2] "Investigation on the Behavior of the Remanence Level of Protective Current Transformers"

Next Issue : April 2017 Cover Story :

LED & Lighting

Special Theme : Control Panel & Switchgear

www.electricalmirror.net 62

MARCH 2017 ||

ELECTRICAL MIR ROR

Contact For Advt. 011-65104350, 9899072636, 09702818098

Focus: renewable energy

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ELECTRICAL MIR ROR

|| MARCH 2017 63

CASE STUDY OF THE MONTH

VARIOUS CASE STUDIES ON OPERATION AND CONTROL SCHEMES FOR GRID SUB-STATION Contdâ&#x20AC;Ś.

1. Introduction:

For the last few months, the response of the readers to the case studies on various incidents is overwhelming. Hence this month we are again choosing the write up on similar kind of studies for developing the synchronisation of practical observation to the theoretical concepts. The analysis of each incident being supported by actual observations had been described during the situation to add awareness amongst the operation, testing and commissioning engineers to know the cause of problems and be helpful for easy rectification of the problems. This can also help to develop economic schemes for the smooth running of the operation and control system in the Grid Sub-Station.

2.1 Actuation of Differential Relay after Shutdown of 160 MVA Auto Transformer:

One 160 MVA 220/132KV Auto transformer was availed with shutdown. After completion of shutdown work, when this transformer was loaded, the differential relay actuated and resulted tripping of the transformer. Similar attempt was done two times and in each case, similar tripping on differential relay resulted.

Actual Observation:

a. This transformer was in loading condition and catering load successfully with the available another 3 Nos of transformers in the network being connected in parallel. b. After taking shutdown for maintenance check up, this transformer was idle charged and stood OK. c. When 132KV system was connected with loads, the current on 132 KV R phase became less as compared to the other phases. d. Now by raising the limit of differential

64

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ELECTRICAL MIR ROR

Er P. K. Pattanaik, is presently working with OPTCL as Asst. General Manager (Elect) in E & MR Division, Bhubaneswar- Odisha and associated with the Protection and Control schemes of Electrical systems.

He is having 24 years of technical experience in Designing, Testing and Commissioning of Protection Control and operational Schemes, project Implementation, co-ordination, operations & maintenance of Electrical Equipments at various LT/ HT/ EHT level Grid Sub- Stations. He has also published around 70 technical papers in different national/international seminars/journals. ele.pkpattanaik@optcl.co.in

current setting to 50 %, the transformer was charged once again. e. This time differential current becomes 19%, and rest of the core for the R phase CT secondary currents were checked on 132 KV side and observed with similar pattern of reduced current as compared to the other phases. f. So it was confirmed with the problem of primary side of the CT.

CT Power TFR Affected LA CT

Fig 2.2

Action Taken:

1. Now this CT was decided for the replacement.

2. After replacement, the transformer was charged successfully.

3. The faulty CT was opened and found with reduction of the Oil level and sparking on internal terminal of the primary conductor ( Photo is attached for reference)

Analysis:

a. Due to reduction of oil level, the required clearance between the primary conductor and top tank got reduced. b. So certain current started to flow through the metal tank of the CT, with other current through the actual primary conductor. c. Now due to flow of part current, the secondary current accordingly became reduced as like it was observed. d. So due to this, the differential current was getting available and causing the tripping of the transformer.

2.2 Tripping of a power Transformer with no connected load.

One of the 132/33KV Power transformer was charged idle with station transformer (33/0.4Kv). This one tripped on Differential and LV back up relay with fault current being HV side (R-170A, Y =170 Amp, B=500A and N=250A) and LV side current being ( r =1A,

STN. TFR

y=1A, b= 2696A and n=2696A).

Observations:-

1. The testing of the transformer was done and found in order.

2. The physical condition of the transformer was also checked and found OK. 3. The LV side B phase LA was checked and found faulty.

4. Required faulty LA was replaced and transformer was charged OK.

Analysis:-

a. With reference to the figure 2.1, it is seen that the LV side LA comes within the protection zone of the transformer, as the LV side covers this zone. b. So during the problem of this LA, this might have been punctured with arching in the system inside. c. So due to result of BN fault in the system, the fault current has raised to higher value as mentioned under observation. d. So due to internal zone, differential relay has been tripped. ||www.electricalmirror.net||

d t l o .

n

e. The earth fault feature being set with high set instantaneous value, this has also tripped.

2.3 Sparking at Control room during lightning:

It was observed with sparking on the metallic structure at the control room for a 220/33Kv grid sub-station during the time of lightning.

Observations:-

1. The voltage of the metallic sheath for some of the running cables were measured with earthing system and found with 35 Volt.

2. The earthing of the cable sheath was checked and found with grounding at Control room end.

3. Now the earthing system of the control room was reviewed.

4. This has only been provided with few independent earth pits but not in MESH( Inter-connection to each other).

2.

3.

4.

5.

the lap of her husband.

Her husband was in sitting posture with folded legs allowing his wife to take rest.

The lady had wore PAYAL (foot ring) on both of the legs and also gold necklace.

There had been snapping of live wire and touching ground and lady died, but not her husband.

So on suspicion of murder, her husband was sent to jail.

Analysis:-

a. Due to snapping of live conductor and touching to ground had resulted of GPR at the point of discharge with development potential contour. b. The lady had wore PAYAL and necklace, was in laying posture. c. So there developed flow of current through her body and she died due to heart

3. On verification it was found with internal crack of the negative electrode s shown.

4. The spark was not resulting during the condition of battery set, when put in charge mode from charger.

5. Then it was decided for the by pass of this cell from the available 110 cells.

6. During the battery set being on Charger

Analysis:-

1. The reason of fluctuation was analyzed and confirmed with the followings 2. In practice, the station load is generally connected with the battery charger with battery system gets connected in parallel for simultaneous charging from the charger.

3. So for the situation of outage of AC supply to charger, this battery bank immediately meets the load of the station load for un-interrupted DC supply.

Closed path for current flow

Analysis:-

a. Because of the problem on the earthing of the network and on the cable system GPR ( Ground Potential Rise) to occur in the system. b. During lightning on as usual manner, GPR results in the earth mat of the grid and causes potential contour. c. Now if any other metallic structure comes in contact to this contour, then certain potential also develops on it. d. So due to the potential difference, current starts to jump and results spark.

Action taken:

1. The earthing of the Control Room was strengthen, by adding extra pits with interelectrode distance being 3meters.

2. All these earth pits were inter-connected to develop earth mesh.

3. Then this mesh was again extended for the connection to GRID mat to develop equi-potential to avoid the development of potential contour.

4. The cables length more than 1 Km, were earthed at the supply sending end and SVL (Surge Voltage Limiter).

2.4 Death of a lady in the lap of her husband:

It was reported death of a lady while taking rest in the lap of her husband.

Observations:-

1. The lady was laying in flat with her head on ||www.electricalmirror.net||

A B A-Position of the lady B- Position of the Man

fibrillation and choke. d. But her husband was in sitting posture and along the same contour, so due to same potential effect he did not get electrocuted. e. Moreover due to metallic path in contact of the contours of different potential, current passed through the body and she died.

4. But during this condition, as 39th cell was loosen like the fig-2.4 as shown, the sudden interruption of the DC supply to the station load was resulting and causing fluctuation of the voltmeter and ammeter.

5. During charging mode, the electrolyte being in charge condition gets expanded for which,

2.4 Fluctuation of Voltage and current pointer of Battery cell:

During checking of the battery voltage by an operator with charger being in OFF condition, it was found with fluctuation of the voltmeter pointer and also the load ammeter.

Observations:-

1. As per the practice, the operator during the operational shift, checked the battery cell voltage, keeping charger in OFF condition and observed with fluctuation of the measuring instruments ( Voltmeter and ammeter) 2. So he attempted for checking of the individual cell and found with slight sparking on 39th cell.

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CASE STUDY OF THE MONTH

the affected part remains inside and sparking does not become prominent.

Moreover during simultaneous charging, the actual load of the station comes under the charger with battery bank in float condition, causing very small current flow.

6. While checking of the battery condition, when charger is made OFF, station load comes to the battery bank with reduction of electrolyte and expose of affected part. So sparking to result by the battery.

Rectification Attended:-

1. For rectification, the charger was allowed to meet the load of station load. Now the dis-connection of battery bank from the charger was made possible due to its floating condition with no station load on it.

2. The inter-connecting link between 38th cell to 39th and 39th to 40th cell was dis-connected as like shown.

3.

By the use of link wire, this cell was by-passed.w

2.5 Bursting of HT bushing of a 220/33 KV Power Transformer: It was observed with bursting of Y phase HT bushing during running condition of the 220/33 KV transformer and all the protections like Differential, REF relays tripped.

Observations:

1. The detail history of the transformer was collected and as narrated that this equipment had been tripped maximum times on OVER VOLTAGE, due to peculiar over voltage condition at grid end.

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2. It was observed with minor abnormal sound at the bushing base for few months back.

3. But on the day of failure, this sound was prominent and resulted with bursting of the Y phase bushing.

Analysis:

1. The HT bushings are generally of OIP type and contain oil and paper as the dielectric medium.

2. These bushings have TAN delta point for the periodical condition monitoring.

3. In practice, this point needs to be shorted to GROUND (body of the TFR) during running condition, for which this has metallic cap.

4. On tightening of the cap, due to spring loaded knob, this point gets shorted to ground.

5. But sometimes due to negligence for putting the cap or non-working of the spring knob, during charging condition the open circuit voltage is developed at this point with respect to ground.

6. For the case of 220 KV bushing this value becomes( 220/â&#x2C6;&#x161;3 KV)and due to looseness or small gap between voltage point and earth, the surrounding air gets ionize and near by insulation stats to damage.

7. In this situation, the gap though was kept on the point but it was loosen condition.

8. Moreover as per the observation, maximum time this transformer had been tripped with OVER Voltage.

9. So each time this over voltage has the impact on the insulation due its magnitude and transient effect with different harmonic frequency.

10. But development of such high voltage and damage of this insulation slowly has caused

ELECTRICAL MIR ROR

failure of the Bushing.

2.6 Failure of maximum insulators during first rain:

For a 132 transmission line, it was found with the failure of insulator stacks of the suspension string, resulting outage of the power system.

Observations:

1. Failure of the insulators was resulting for the particularly during drizzling only.

2. But after first few rain falls, this situation got reduced

Analysis:

1. The fail insulator was checked and found with cracks with bead of pores on it.

2. So it was analysed as follows a. During manufacturing, there remains some mini/micro cracks and pores, the testing of which generally waived due sample testing practice. b. During dry weather, these insulators do not behave abnormal. c. But for the situation of first spell of rain, the impure water with dust and foreign particles enter the pores and cracks. d. So the dielectric property of the insulators gets reduced with reduction of creepage distance. e. So flow of leakage current and abnormal internal heating of the insulator causes the failure of the stacks. f. But after few rains, the left over insulators being wet tested with the existing line voltage remain intact and cater the supply successfully.

||www.electricalmirror.net||

Reliabe Winding Solution

2017

2nd Edition

Coil Winding, Stamping & Transforming Manufacturing Exhibition & Conference 16-17-18 MARCH 2017, Hall No.5 Bombay Exhibition Centre Mumbai, India

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ELECTRICAL MIR ROR

|| MARCH 2017 67

REPORT

ALL OF YOU ARE FED WITH A BIG LIE…!!

Life of Transformer is 20-25 Years

(The fact is that a transformer seldom fails during 20 – 25 years of its service life. It fails during first 10 years of its life. As it stands out of warranty period, it does not come to highlights. If it has survived 25 years, the life can be extended to 50 years)

Would You Like Your Transformer To Give You 50-60 Years Of Life?

YES, IT IS POSSIBLE

For this to know, you must first understand what kills a transformer?

We Are Neglecting Accidents And Age-Related Aspects Are Explained.

What changes takes place inside the transformer that it fails with-in 8-10 years?

WHO ARE THE BIGGEST ENEMIES CAUSING PRE-MATURE DEATH OF A TRANSFORMER

MOISTURE

EXCESS TEMPERATURE RISE

AGE OF INSULATION

Liquid insulation- Oil Solid insulation- Wood, paper, pressboard

Reversible by filtration and reclamation Non-reversible

Once a transformer is allowed to operate at violated temperature range for a long period, the damage is permanent and not reversible because life of solid insulation can-not be reversed. Any amount of oil filtration can-not bring back the transformer to original state. The loss is permanent.

Can You Allow This To Happen? …And Then Try To Compensate It Using In-Correct Methods? Or You Prefer Prevent This To Happen?

Only Fools Opt For Cure. Wise Choose Prevention

First of all, does it not surprise you that why a device called transformer, which is the heart of any industry, was designed to be hygroscopic? Only to be killed by cruel moisture present in the air?

We Shall Come Back On Above Later. Let Us Roll Back First To Address Moisture Problems In Existing Transformers With “A” Class Insulation.

MOISTURE CAUSES OF MOISTURE

EXTERNAL INTERNAL

HOW

TO

Atmosphere Free-breathing of a T/f Chemical reactions among copper , Iron and oil

PREVENT MOISTURE TRANSFORMER ?

ENTRY

TO

Sealed Breathing System – To Prevent External Moisture

The conventional Silica-gel breathers are main culprits for deterioration of transformers.

How could anyone imagine that few Kg. of silica-gel can prevent transformer to become wet?

And specifically when this poor device is mostly not maintained by replacing Silica-gel frequently. How a manufacturer and users both can expect a technician to ride a pole to replace silica-gel in breather of a pole mounted transformer? Does it not seem ridiculous? It definitely is.

For medium and large transformers, air-cells were introduced to isolate the transformers from open atmosphere. Small transformers were allowed to die pre-mature.

But There Were Discrepancies And Drawbacks With Air-Cells:

threat of free-breathing system.

2. The repair of a puncture was difficult and called for long outage period.

Trafotech introduced a very simple system (Inventor: Anurag Malhotra) which was not prone to puncture and capable to keep transformers 100% isolated from open atmosphere.

There are two types of devices, one for small distribution transformers and another for medium & large transformers.

These devices do not permit slightest moisture to enter the transformer and hence responsible for life-extension of transformer by keeping transformers dry to a safest level.

The devices are maintenance-free and operate without power.

OIL-PURIFIER: to extract moisture generated inside the transformer.

More than half of the moisture problem gets attended when sealed breathing system is installed.

OIL-PURIFIER is installed on transformer which maintains good quality of oil by 24 x 7 purification and keep the transformer dry.

This device attends following in the oil: 1. Water content- maintains low water content levels 2. Acidity – does not allow transformer to become acidic to an un-acceptable level 3. Specific resistance – improves resistivity The device operates without any power. Basic principle on which it can extract more moisture from transformer is simple physics.

To extract moisture from innermost part of solid insulation, through oil,

“Windings Must Be Hotter Than Oil”.

This pre-condition only can extract moisture from solid insulation.

Why Filter Machines Fail To Make A Transformer Dry?

Because they can-not fulfill above mentioned pre-condition i.e. windings being hotter than oil during oil filtration. This does not happen because transformer oil filtration is carried out while transformer is under shut-down; and then the reverse happensoil becomes at higher temperature than windings and there-by releases all its moisture to solid insulation. It can make the oil good, not the transformer. As soon as the transformer is energized and put on load, the dry oil again becomes wet due to migration of moisture reverse from winding to oil.

Generally, user is un-aware of the fact that oil hates moisture.

It can store very little moisture and balance is released to solid insulation. Can you imagine the moisture storage capacity of solid insulation? 300 times more than oil..!! Yes, you rightly read this. Solid insulation can store 300 times or more moisture in it.

The moisture of solid insulation migrates to oil when the transformer is on load, when winding is hotter than oil. So, what was the ideal time to extract moisture from transformer through oil? Exactly, when it was on maximum load. The reverse happens when an oil filter machine is used.

1 If they puncture, it was not noticeable immediately leaving the transformer in

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||www.electricalmirror.net||

ELECTRICAL MIR ROR

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REPORT

Can any user operate conventional filter machine on a loaded transformer?

NO

Oil purifier provided by Trafotech as in-built part of T/f performs this without any power on a loaded transformer and keeps the transformer to a safe dry level.

Oil purifier and Sealed breathing system provided by Trafotech complement each other to keep transformer dry to maximum level possible.

It must be fairly under-stood that to keep a transformer dry, both systems must work simultaneously.

Both the life extension devices can be installed on any working old or new transformer without altering the original design of transformer, with few hours of shut-down. The devices are not expensive but provide considerable life-extension to transformers permitting huge savings.

The transformers installed with above life extension devices do-not require oil filtration through filter machines. The Trafotech transformers are marked with “DO NOT FILTER” warning sign.

The cost of oil filtration is thus saved, and this reduces the total owing cost of a transformer, which is defined below: Total owing cost of a transformer = Capital cost + Cost of losses + Cost of maintenance It could be seen that increase in life of insulation by keeping it dry can extend the life of a transformer.

Life of a transformer = Life of transformer insulation Other parts like core and copper are not prone to ageing For reference, we furnish below safe operating levels of a transformer:

Over-all Moisture level in a transformer Moisture is calculated by dry weight of (including oil and solid insulation) insulation 0.5%

Excellent

1%

Good

1.1 to 2%

Fair

2.1 to 3%

Danger

3% and above

Lying on death bed

Mechanical Stability Of A Transformer The life of transformer has direct relation with its ability to stand secondary short circuits.

So, an excellent power transformer with 2000 Kg of solid insulation can have 0.5% moisture, uniformly distributed i.e. 10 lt. of water.

Ever thought at which moisture level your transformer left the manufacturer factory??

The health of oil reflects transformer health. In case ageing of paper happens, its DP value may fall down from 1200 to 250. This reflects in oil in the form of furans. The relation is shown below: 2 Furaldehyde content in ppm DP value of paper

Significance

<0.1

800-1200

Healthy

0.1-1

500-800

Moderate deterioration

1-10

250-450

Extensive deterioration

>10

<250

End of life

The remaining life of a transformer can be assessed by conducting furan analysis test to be read in co-relation with DGA, Resistivity and other properties of oil and values/ history of transformer. It can mislead, If not read properly.

EXCESS TEMPERATURE RISE Causes of excess temperature rise

EXTERNAL

INTERNAL

Overloading Faulty cooling system High ambient temperature Faulty design Blocked cooling ducts Excess stray losses

Overloading- While IS- 6600 permits overloading, it is not without charging the life of a 70

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ELECTRICAL MIR ROR

transformer. 6 degree C violation in temperature on higher side can reduce the life of insulation to half than its rated life.

Identical loads in different seasons impose different levels of threats on transformers in India due to high variation in basic ambient temperature from 0 degree C to 47 degree C. For example, 100% load on transformer in January and June have different meanings in North India. At same load, the utility factor is different.

Excess temperature rise causes more faster deterioration of solid insulation (fall of DP value) thereby eating the life of a transformer.

Excess temperature in association with moisture present in transformer, due to catalytic effect, can bring catastrophic failures. To get maximum life out of A class insulation transformers manufactured as per IS 2026, they must not be operated beyond 85 degree C winding temperature.

The transformers which are operated at 70-75% load give back benefit in the form of less I²R losses. For example, a 20 MVA transformer with load loss of 80 KW will have load loss of 20 KW when operated at 10 MVA. This saving of 60 KW pays back the cost of transformer in 3 years. Additionally, you get extended life of transformer.

It is wise to adopt additional heat dissipation methods on existing working transformers which are heavily loaded, as per wisdom of site engineers.

The windings shrink after 8-10 years of service and hence creating a gap between winding top and pressure tightening system. The movement of windings during secondary faults allows insulation rubbing further leading to failures.

Trafotech transformers are provided with auto-tightening system on windings to make-up the shrinkage automatically, without opening the transformer for which IS 10028 (3) insists.

The core is also locked from all sides to prevent abnormal dis-location.

Mechanical dis-location of windings

All the protections provided on a transformer operate after the fault has happened. None warns about a probable future failure.

Winding dis-loaction at present is monitored by SFRA test.

But this is a signature test and the site engineers are mostly unable to read the results. The change in instruments also causes a lot of variations.

There was a strong need of a warning signal to user before-hand, regarding on-coming failure of a transformer so that planned repair or outage could be organized and facing it as a sudden accident could be prevented.

Trafotech has provided this feature in power transformers.

This is called “ Winding Dis-location Monitor” invented & patented by Anurag Malhotra. This also replaces use of impact recorders to know dis-locations during transit.

Generally, mechanical dis-location of windings takes place ||www.electricalmirror.net||

first in case of a failure of a transformer due to external severe faults. But unfortunately, it remains un-noticed. Many transformers can be saved if this is attended at right time.

Such kind of repeated faults finally disturb the required electrical clearances to an un-acceptable level and spark happens.

In Trafotech transformers, a signal appears on the remote panel if any of the winding has dis-located beyond a certain limit. Hence, user gets a warning signal prior to actual failure and this failure can be prevented and managed by careful and wise decisions.

A. Would You Use Fire Prevention System To Save Transformers?

OR B. You Would Not Allow The Fires To Happen?

All of you will correctly answer (b)

Trafotech transformers provide transformers which are fire safe.

Trafotech transformers are filled with special liquid which has very high fire

point ( more than double of mineral transformer oil) These transformers are safe to use in chemical atmosphere, nuclear power plants, refineries and fertilizer plants or any other application where fire threat exist.

ON-LOAD TAP CHANGERS are the general cause of creating fires in transformers.

This is introduced first time on this Globe.

Coming Back To Initial Question Raised By Us, Why Transformers Are Manufactured With Hygroscopic Insulation And Allowed To Become Wet? Trafotech has the answer… !!

Trafotech provide transformers which have B and H class insulation, which are non-hygroscopic (not affected by presence of moisture) The transformers operate at elevated temperatures. All parts of transformer, including oil, permits temperature rise as per B and H class insulation.

Trafotech has also internally tested a transformer which is filled with water

in place of oil. It will be launched soon.

Other features of Trafotech transformers Magnetic circuit brought out on tank top cover Magnetic circuit tested at 5 KV in place of conventional 2 KV Residual drain plug provided All inspection covers provided with jack screws Rain sheds provided on conservator Low sound level Provided with sealed breathing system and oil purifier as built-in feature.

ANURAG MALHOTRA CEO – United Trafotech Pvt. Ltd. Director-GEW Trafotech Pvt. Ltd.

Executive Director- Mahashakti Energy Ltd. OLTCs of Trafotech transformers are filled with this special oil in which fire accidents do-not take place.

The special oil has capacity to hold moisture 16 times more than mineral Statement about ownership and other particulars of Electrical Mirror, Delhi, as required under Rule 8 of the Registration of Newspapers (Central) Rules, oil without sacrificing the di-electric values.

1956

Would You Like To FORM IV (See Rule 8) Enhance Capacity 1. Place of Publication : Delhi Of Your Existing 2. Periodicity of its Publication : Monthly Transformers By 153. Printer’s Name : Bright Tree 20% ?

Trafotech has the answers…!!

Would You Like To Double The Operations Of Oltc In A Transformer Without An Overhaul?

Trafotech has the solution by which

above is achieved. This saves the cost of overhaul and also increases safety level.

Would You Like To Further Extend The Life Of Oltc By Installation Of “Sealed Breathing System” Specially Designed For Oltcs?

The system permits total isolation of OLTCs from atmosphere and it permits escape of gases generated during tap change to atmosphere. ||www.electricalmirror.net||

Whether Citizen of India ? : Yes Address : C-40, Gate No. 4, Okhla Industrial Area, Phase - II, New Delhi - 110020 4. Publisher’s Name : Usha Whether Citizen of India ? : Yes Address : 13/455, Block No. 13, Trilok Puri, Delhi - 110091 5. Editor’s Name : Alka Puri Whether Citizen of India ? : Yes Address : 253 - B, Pocket - C, Phase - II, Mayur Vihar, Delhi - 110091 6. Name and Address individuals who own the newspapers and partners or shareholders holding More than one per cent of the total capital.

I Usha, hereby declare that the particulars given above are true to the best of my knowledge and belief.

Date : 1 March 2017

Sd/Usha Signature of Publisher ELECTRICAL MIR ROR

|| MARCH 2017 71

PRODUCT INFO

FLIR Launches New Generation of Advanced Thermal Imaging Cameras for Electro-Mechanical, Plant and Building Professionals

Completely Redesigned Exx-Series Offers Intelligent Interchangeable Lenses, Laser-Assisted Autofocus, Higher Resolutions, and a Larger, Brighter Touchscreen FLIR Systems, Inc. (NASDAQ: FLIR) announced three new Exx-Series advanced thermal imaging cameras for electrical, mechanical, and building applications: the FLIR E75, E85, and E95. The redesigned, Wi-Fi-enabled Exx-Series features intelligent interchangeable lenses, laser-assisted autofocus modes and area measurement functionality, improvements to FLIR’s patented MSX® imaging technology, and a larger, more vibrant 4-inch touchscreen. These distinctive features, combined with increased sensitivity and increased native resolution, will help professionals identify hot spots or building deficiencies before potential problems become expensive repairs.

In redesigning the Exx-Series, FLIR developed a new range of compact intelligent, interchangeable lenses that the camera automatically recognizes and calibrates, eliminating the need for manual calibration. The Exx-Series now also features laser distance measurement that assures precise autofocus to improve temperature measurement accuracy, and specifically for the FLIR E85 and E95 models, provides the data for on-screen area measurement in square feet or meters. In addition, the FLIR E85 and E95 models offer increased thermal detector resolutions with up to 464×348 (161,472 pixels), and measure temperatures up to 1,500 degrees Celsius.

In conjunction with FLIR Tools™, the FLIR E75, E85, and E95 are the first Exx cameras to offer UltraMax®, FLIR’s embedded, super-resolution process that improves effective resolution by four times – up to 645,888 pixels – and thermal sensitivity by up to 50 percent. All models also feature significant improvement to FLIR’s MSX technology, which now utilizes a 5-megapixel visual camera for improved image clarity and readability.

These improvements, combined with a display that is 33 percent brighter and 30 percent larger than previous Exx models, yield more vibrant and detailed thermal imagery.

The Exx-Series cameras also feature a rugged, water-resistant design, and scratch-resistant Dragontrail™ cover glass over an opticallybonded, projected capacitive (PCAP) touchscreen.

A simplified user interface delivers faster, more intuitive operation, and coupled with enhanced 72

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Wi-Fi, Bluetooth and Meterlink® connectivity, archiving and report generation has never been easier.

“Redesigned from the handle up, the new series of Exx cameras is a significant achievement in terms of advanced functionality, performance, and ease of use in thermal cameras for electromechanical, plant, and building inspections,” says Andy Teich, President and CEO at FLIR. “With an ever-broadening base of users who demand thermal cameras that are compact, capable and easy to use, the advanced Exx cameras check every box.”

The FLIR E75, E85, and E95 cameras will be available for sale in March through established FLIR distribution partners. For more information, visit www.flir.in/exx-series.

About FLIR Systems FLIR Systems, Inc. is a world leader in the design, manufacture, and marketing of sensor systems that enhance perception and awareness. FLIR's advanced thermal imaging and threat detection systems are used for a wide variety of imaging, thermography, and security applications, including airborne and ground-based surveillance, condition monitoring, research and development, manufacturing process control, search and rescue, drug interdiction, navigation, transportation safety, border and maritime patrol, environmental monitoring, and chemical, biological, radiological, nuclear, and explosives (CBRNE) detection. For more information, go to FLIR's web site at www.FLIR.in.

referenced in this release, changes in pricing of FLIR's products, changing demand for FLIR's products, product mix, the impact of competitive products and pricing, constraints on supplies of critical components, excess or shortage of production capacity, the ability of FLIR to manufacture and ship products in a timely manner, FLIR's continuing compliance with U.S. export control laws and regulations, and other risks discussed from time to time in FLIR's Securities and Exchange Commission filings and reports. In addition, such statements could be affected by general industry and market conditions and growth rates, and general domestic and international economic conditions. Such forwardlooking statements speak only as of the date on which they are made and FLIR does not undertake any obligation to update any forward-looking statement to reflect events or circumstances after the date of this release, or for changes made to this document by wire services or Internet service.

Forward-Looking Statements

The statements in this release by Andy Teich and the other statements in this release about the products described above are forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements are based on current expectations, estimates, and projections about FLIR's business based, in part, on assumptions made by management. These statements are not guarantees of future performance and involve risks and uncertainties that are difficult to predict. Therefore, actual outcomes and results may differ materially from what is expressed or forecasted in such forward-looking statements due to numerous factors, including the following: the ability to manufacture and deliver the systems

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For more information about thermal imaging cameras or about this application, Please contact : FLIR Systems India Pvt. Ltd. 1111, D Mall, Netaji Subhash Place, Pitampura New Delhi - 110034 Tel: +91-11-45603555 Fax: +91-11-47212006 E mail : flirindia@flir.com.hk Website : www.flir.in

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EH Electronics Housings by Phoenix Contact Simple, Versatile and Efficient

Many housing customers demand electronics housings that can be used for devices that are available with good aesthetics, innovative features and in the lower pricing sector. The EH electronics housings fulfil this requirement.

The new EH housing system is designed for universal device applications with 7 overall widths, 2 overall heights and a range of different cover versions. In total, there are 112 possible combinations available to the device manufacturer.

In addition to the modern design, this housing range excels, thanks to numerous other features.

Integrated vents ensure good ventilation. The device is mounted simply by snapping it onto symmetrical DIN rails according to EN 60715.

Alternatively, wall mounting is also possible. The housings are provided with integrated labeling fields for device marking.

The EH are combined with COMBICON connection technology from the standard range or from the Basicline range. Pluggable as well as fixed connection technology can be used in the widest number of positions and pitches.

Main features and customer benefits:

1. 2 overall heights (110.5 mm, 54 mm) and 7 overall widths (22.5 to 90 mm) : Easy creation of modular device systems featuring a uniform design 2. 3 cover versions per overall width: closed, as well as single- and double-sided connection: For application-specific device design 3. Open terminal installation space to allow variation in PCB connection technology: The use of plug-in and hardwired connection technology with variable numbers of positions and pitches 4. PCBs can be installed in all 3 space directions: For a functional device concept 5. Simple PCB shape: Cost-effective PCB production 6. Integrated marking field: For fast device marking 7. DIN rail or wall mounting: Range of application options irrespective of sector 8. Mounting by snapping on instead of screwing: its time saving during device assembly

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Connect your conductors in easy, fast and reliable way

Phoenix Contact’s COMBICON product range offers a variety of connectors loaded with “Push-In Spring” technology which enables you to connect your wires in much more easier and faster way. Direction of the cable entry is no more a challenge.

Pluggable with Spring Connection Technology • Ratings – 6A/ 250V to 76/ 1000V • Wire cross-section – 0.14 Sqmm to 16 Sqmm • Pitch – 2.5 mm to 10.16 mm Pluggable with Screw Connection Technology • Ratings – 8A/ 160V to 125A/ 1000V • Wire cross-section – 0.14 Sqmm to 35 Sqmm • Pitch – 3.5 mm to 15 mm Fixed with Spring Connection Technology • Ratings – 4A/ 250V to 125/ 1000V • Wire cross-section – 0.14 Sqmm to 35 Sqmm • Pitch – 2.5 mm to 15 mm Fixed with Screw Connection Technology • Ratings – 6A/ 250V to 232A/ 1000V • Wire cross-section – 0.14 Sqmm to 95 Sqmm • Pitch – 2.54 mm to 20 mm For further details Phoenix Contact India Pvt. Ltd. F-26/2, Okhla Industrial Area Phase -2, New Delhi – 110020 e-mail- adverts@phoenixcontact.co.in

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PRODUCT INFO

Far Away Yet Connected The New Thermal Imagers from Testo are Smart & Networked

The measurement technology expert Testo launches four new thermal imagers in the market.

The unbeatable price-performance ratio of the models testo 865, testo 868, testo 871 and testo 872 clearly show that top quality "Made in Germany" and an attractive price are not mutually exclusive.

The new Testo innovations are a clear exclamation mark in the tough thermal imager market: They have a resolution of up to 320 x 240 pixels. With the testo Super Resolution technology included as standard, this can even be increased at a PC to 640 x 480 pixels. No comparable thermal imager has better image quality.

Work smart and networked

Apart from the entry model testo 865, all thermal imagers can also be connected to the testo Thermography App. The App, available for iOS and Android, turns the user's smartphone

into a second display and a remote control for the thermal imager, and serves to create compact reports quickly on site, to save them online and send them by e-mail.

The models testo 871 and testo 872 can be additionally connected wirelessly with the thermohygro meter testo 605i and the clamp probe testo 770-3. This allows fast and clear identification of where exactly the thermography is to be done in any given climatic condition or at what load a switching cabinet is running.

Automatic setting of emissivity

The setting of emissivity and reflected temperature, both indispensable for precise thermal images, were time-consuming and with regard to reflected temperature, were less than accurate by now. These irregularities can be solved with the testo -Assist.

In order to use this function, a special sticker ( -marker) is attached to the measurement object.

Via their integrated digital camera, the thermal imagers testo 868, testo 871 and testo 872 recognize the sticker, determine the emissivity and reflected temperature and set both values automatically.

Objectively comparable images

The newly developed testo Scale Assist function solves the problem of the users by adjusting the colour distribution of the scale to the interior and exterior temperature of the measurement object and the difference between them. This ensures objectively comparable and error-free thermal images of the thermal insulation behaviour of a building.

The thermal imagers testo 865, testo 868, testo 871 and testo 872 are now available directly from Testo or expert channel partners.

For more info : write to info@testoindia.com or visit www.testo.in

MECO “Digital Multimeter” MECO introduced new Digital Hand held Multimeters Model 153B-TRMS & 171B-TRMS.

153B - TRMS & 171B – TRMS is 3-5/6 Digits 6000 Counts Autoranging

Digital Multimeters (TRMS) are hand held having AC and DC Current and Voltage Measurement, Resistance, Capacitance, Frequency are key features.

Both Models having LCD Backlight, Low Batt Indication, Light Weight and Holster are additional features. Both Models are user friendly and easy to use.

Specification :

• Voltage Range upto 1000 V DC & 750V AC • Current Range upto 20A AC & 20A DC, • Resistance upto 60 Meg Ohms

• • • •

Capacitance upto 9.999mF Frequency from 99.99Hz – 20.00 MHz. Duty Cycle, APO Function Temperature & REL Max / Min Measurement (171B-TRMS) • Diode Test, Audible Continuity, Data Hold Function • Accessories: Test Leads (Pair), Holster, Battery (Installed) & Instruction Manual.

For Details Please Visit : Website : www.mecoinst.com

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ABB India Ltd. ...................................................................................... IFC

Mtekpro Technologies Pvt. Ltd. ............................................................. IBC

Automation Expo 2017........................................................................... 57

Next Gen Equipment Pvt Ltd .... ......................................................... 77

Aeron Composite Pvt. Ltd. .................................................................... 47

Omicron Energy Solution P. Ltd. ........................................................... 09

Cable & Wire Expo ............................................................................... 75

Phoenix Contact (India ) Pvt. Ltd.......................................................... 19

Central Power Research Institute .......................................................... 23

Radite Energy Infra Solutions Pvt Ltd. ................................................. 27

CWST - Expo 2017 ................................................................................ 31

Ramelex Pvt. Ltd. .................................................................................. 39

Flir Systems India Pvt. Ltd. .................................................................. 17,BC

Scope T & M Pvt. Ltd. ......................................................................... 03

GEW Trafotech Pvt. Ltd. ....................................................................... 69

Solar Today Expo ................................................................................. 63

Green-Watt Techno Solutions Pvt. Ltd. ................................................. IFG

Sonel Instruments Pvt Ltd ................................................................... 80

GTB Transformers .................................................................................. 51

Sterlite Power ......................................................................................

HPL Electric & Power Ltd. .................................................................... 01

Testo India Pvt Ltd ............................................................................... 11

Indian Transformers & Electricals ......................................................... 43

The Motwane Mfg. Co. Pvt. Ltd. .......................................................... 79

KLJ Polymers & Chemical India ........................................................... 53

Transwind Technologies ........................................................................ 67

M & I Materials India Pvt. Ltd.............................................................. 13

Vashi Electricals Pvt Ltd ....................................................................... 25

Meco Instruments Private Ltd. .............................................................. 15

Wheels Polymers Pvt. Ltd. ................................................................... 29

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Metering India 2017 ............................................................................. 37

Next Issue : April 2017

Cover Story : LED & Lighting

Special Theme : Control Panel & Switchgear

Focus: renewable energy

www.electricalmirror.net Contact For Advt. 011-65104350, 9899072636, 09702818098

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EVENT DIARY

Month/Date Location Web :

: 16 - 18 March 2017 : BEC, Mumbai, India www.cwstexpo.com

Month/Date Location Web :

About Event

The Coil Winding and Transformer Industry is growing strength by strength, every day. The transformer Industry in India is well versed and matured enough into reliable supplier of all types of transformers and can meet country’s demand and exports market for sub-transmission system.

Month/Date Location Phone Web :

: 7 - 9, April 2017 : BIEC, Bangaluru, India : +91-22-65777990 www.solartodayexpo.com

About Event LED India Expo 2017 is a concurrent show happening together. Both the shows will host leading players in solar energy sector and from LED industry that will include manufacturers, suppliers, contractors, consultants from India and many other countries.

Month/Date Location Phone Email Website

: 06- 07 April 2017 : New Delhi, India www.events.ieema.org/meteringindia

About Event METERING INDIA, Seminar has been a catalyst of change in the Indian Energy Metering Industry. An interactive and thought provoking bi-yearly event, it enjoys widespread popularity amongst the stakeholders of the metering Industry. IEEMA Energy Metering Division is pleased to invite your participation at the Seventh edition in the series.

Month/Date Location Web :

: December 5–7, 2017 : Mumbai, India www.intersolar.in

About Event Cable & Wire Fair 2017 (CWF17), the second edition will take place from 5 – 7 October 2017 at Hall 12 & 12A, Pragati Maidan, New Delhi, India

: 09-12, August 2017 : Bombai Exhibition Centre, Mumbai : +91-22-22079567 / 22073370 : arokiaswamy@iedcommunications.com : www.iedcommunications.com

ICON MEDIA 375-G, IIIrd Floor, Pocket Delhi Month/Date : 5 – -II, 7 October 2017- 110091 Location : New Delhi, India Tel : +91 11 6510 4350, About Event Web : http://www.cablewirefair.com Fax : +91 11 22753088 Automation Expo, the largest Automation & Instrumentation exhibition of South-East Asia A Outlook of the Construction & Infrastructure Industry is all set to make a mark in 2017 as well. Under the valiant leadership of About Event : subscribe@constructionmirror.com Mr. M. Arokiaswamy, IED Communications has been successfully hosting Automation Expo Intersolar India is Email the country’s largest exhibition and conference for the solar industry. It and achieving its objective to fuel innovation and growth for 14 years now. takes place annually at the Bombay Exhibition Centre (BEC) in Mumbai.

Web : www.constructionmirror.com

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RNI Regd. No. DELENG/2011/39089 . Postal Regd. No. DL(E)-20/5393/2015-17.

Posted at Krishna Nagar P. O. Delhi - 110051 on 14th/ 15th of every month.

English . Monthly . Date of Publication 5th of Every Month.

NE W

Exx-Series

FLIR

™

ADVANCED THERMAL IMAGING REIMAGINED FROM THE HANDLE UP

FLIR redesigned the Exx-Series from the handle up to deliver the best performance, resolution, and sensitivity of any pistol-grip handheld thermal camera.

The new Exx-Series cameras are packed with the features you need to quickly troubleshoot electrical distribution and mechanical systems, so you can avoid equipment failures, increase plant safety, and maximize up-time.

FLIR Exx-Series cameras now offer:

Easily detect mechanical problems

Images for illustrative purposes only.

• Interchangeable, auto-calibrating lenses • Up to 464 x 348 IR resolution • Our best MSX® enhancement • UltraMax™ processing for 4x pixel resolution • A larger, 4” display that’s 25% brighter • A responsive new interface • Improved reporting options

www.flir.in/exx-series

Easily detect electrical faults

For more details call us on: +91-11-4560 3555 or write to us at flirindia@flir.com.hk FLIR Systems India Pvt. Ltd. 1111, D Mall, Netaji Subhash Place, Pitampura, New Delhi – 110034 Fax: +91-11-4721 2006 | Website: www.flir.in

Exx 18x25 ad.indd 1

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