Power Quality Improvement with Multilevel Inverter Based IPQC for Microgrid

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International Journal for Modern Trends in Science and Technology ISSN: 2455-3778 :: Volume: 05, Issue No: 07, July 2019

Power Quality Improvement with Inverter Based IPQC for Microgrid

Multilevel

Maddala Uadykiran1 | A Durga Prasad 1PG

Scholar, Department of EEE, Sir C R Reddy College of Engineering, Eluru, India.

Professor, Department of EEE, Sir C R Reddy College of Engineering, Eluru, India.

2Assistant

To Cite this Article Maddala Uadykiran and A Durga Prasad, “Power Quality Improvement with Multilevel Inverter Based IPQC for Microgrid”, International Journal for Modern Trends in Science and Technology, Vol. 05, Issue 07, July 2019, pp.-39-43.

Article Info Received on 07-June-2019, Revised on 11-July-2019, Accepted on 17-July-2019, Published on 21-July-2019

ABSTRACT A micro grid is a hybrid power system consists of several distributed resources and local loads .Now a days with increasing on a day to day life micro grid plays a vital role in power generation using Renewable Energy Sources. Usage of power electronic devices in a micro grid results in harmonic generation and leads to various power quality issues. Inorder to overcome voltage fluctuations and over current a magnetic flux control based variable reactor is proposed. The performance of IPQC can be verified by using MATLAB/SIMULINK. KEYWORDS: Power Quality Improvement, Microgrid, IPQC, Copyright © 2019 International Journal for Modern Trends in Science and Technology All rights reserved.

I. INTRODUCTION The strength is neither be created nor destroyed alternatively it are frequently regenerate from one sort to a different. The technology of AN energy is nothing then again the conversion of various one-of-a-kind sorts of energy into AN power. The electric powered energy is generated in bulk at the producing stations that are referred to as strength stations. The generated strength is demanded by means of the customers. This purpose due to the fact of electricity losses and strength quality troubles inside the transmission lines FACTS machine is added to cut lower back such issues. small grid ends up in positive distribution in geographic vicinity all distribution consists of tremendous electricity processor to control and display the facility trade between the grids [1-3]. once such processor get definitely exploited it ends up in high electricity great problems and strength 39

consumption with the aid of creating slender band verbal exchange and native administration system full small grid is exploited with marginal investment. A forty eight pulse structure electrical converter used to be developed by way of cascading many devices of 3 degree diode clamped shape electrical converter with the help of section moving electrical device. It ends up in high fee and prolonged delays this motive serious deficiency in power transmission capability whereas distribution [4]. Interline Power Flow Controller is one in each of the advanced controller in versatile AC equipment mechanism controller it completely compensates collection and manages strength waft inside the machine [5].

To at the equal time administration the facility flow 2 convertor model d-q orthogonal was once added inside the microgrid. By ability that of transmission attitude version collection voltage is inject within the administration vicinity and

International Journal for Modern Trends in Science and Technology

Maddala Uadykiran and A Durga Prasad : Power Quality Improvement with Multilevel Inverter Based IPQC for Microgrid

therefore the machine receives over paid [6].

Microgrid ends up in fine distribution in geographic place all distribution consists of effective energy inside the management vicinity processor to manipulate and monitor the facility alternate between the grids. once such processor get absolutely exploited it ends up in high energy satisfactory issues and power consumption via growing slender band verbal exchange and native management formula full small grid is exploited with marginal investment and principally small grid are regularly capable to disconnect from the microgrid masses from the disturbance and protects the transmission from harmonics [7]. By grid interfacing convertor machine the traditional sequence and parallel shape is customized. 2 3 phase 4 leg inverters is tend to construct grid interfacing machine to compensate harmonic contemporary it will enlarge the complication and losses inside the gadget [8]-[9]. Distributed generator now not solely inject power to the grid it conjointly enhance strength quality. By capability that of hunch management technique it autonomously compensates voltage unbalances lively and reactive hunch administration [10].A bendy AC distribution system targets to increase the facility fine and reliableness in microgrid, the planning of administration algorithms and prolonged kalman filters is supposed for frequency chase and to extract harmonic in grid voltage and cargo modern-day in small grid.

By minimizing the complete system planning and operation cost and price of load shedding cooptimization of electricity device is taken over to enlarge the monetary and reliability of the grid [11].

The main advantage of multilevel inverters is that the output voltage can be generated with a low harmonics. Thus it is admitted that the harmonics decrease proportionately to the inverter level. For these reasons, the multilevel inverters are desired for immoderate electricity applications[12].

However, there is no scarcity of disadvantages.

Their manipulate is a complete lot higher problematic and the methods are despite the fact that now now not greatly used in industry. In this paper, modeling and simulation of a multilevel inverter the use of Neutral Point-Clamped(NPC) inverters have been performed with motor load the usage of Simulink/ MATLAB program. In the first section multilevel inverter manipulate strategies are presented earlier than to element a locate out about of seven-level inverter in the 2nd section.

Total Harmonic Distortion (THD) is mentioned in the 1/3 section. The goal is to highlight the 40

restriction at which the multilevel inverters are no longer effective in decreasing output voltage harmonics [13, 14].

II. IPQC A. System Configuration The novel IPQC can be established in sequence and parallel in microgrid or factor of frequent coupling (PCC). For simplicity, the IPQC is established in PCC. Fig. 8 indicates the three-phase special gadget configuration of the IPQC with transformer and inverter. and characterize the source voltage and impedance of conventional electricity supply, respectively. The passive filters, which have the function of absorbing the harmonics, are shunted in each sides. The principal winding of a transformer is inserted in collection between the conventional strength utility and the microgrid, whereas the secondary winding is linked with a voltage-source PWM converter. is the voltage of the dc aspect of the inverter. The microgrid consists of a harmonic load, a photovoltaic mobilephone system, a battery storage system, and a regular load. The proposed IPQC has the following functions.

Fig.1. Circuit of the Proposed IPQC. B. Power Flow Control When the strength glide control and the fault cutting-edge limiter are of concern, only the vital is taken into account. In phrases of the previous analysis, the primary winding well-knownshows adjustable impedance + (1 − Îą) . With the alternate in coefficient Îą, the equivalent impedance of the main winding can be achieved, which is shown in Table I. Therefore, when the foremost winding is linked in collection in circuit, it can be utilized to manage the strength waft between the

International Journal for Modern Trends in Science and Technology

Maddala Uadykiran and A Durga Prasad : Power Quality Improvement with Multilevel Inverter Based IPQC for Microgrid

conventional power utility and the microgrid or the inner electricity drift of the microgrid. The schematic of power float control is proven in Fig. 9 when the novel variable reactor is connected in series between the sending and receiving ends.

Suppose that the equal impedance + (1 − Îą) of the variable reactor is R + jX. In phrases of the vector sketch in Fig.9, the following equations can be obtained: two

important addressed as relevant multilevel inverters, are cascade converter, neutral-pointclamped (NPC) inverter, and flying capacitor inverter.Some features for these new converters embody industrial drives, flexible ac transmission structures (FACTS),and automobile propulsion as verified in Fig.12. One vicinity the place multilevelconverters are more regularly than no longer appropriate is that of renewable photovoltaic electrical energy that effectivity and electrical strength first-rate are of wonderful worries for the researchers

Fig.3.single leg of five level NPC inverter.

Fig 2: Power flow control principle and its vector diagram.

C. Multilevel Inverter Multilevel electrical energy conversion used to be once as quickly as first introduced extra than two many years ago. The not unusual thinking consists of making use of a greater extent of energetic semiconductorswitches to feature the energy conversion in small voltagesteps. There are a number of blessings to this approach whencompared with the traditional power conversion approach.The smaller voltage steps lead to the manufacturing of higher powerquality waveforms and moreover avert voltage (dv/dt) stress onthe load and the electromagnetic compatibility concerns.Another fundamental characteristic of multilevel converters is that thesemiconductors are wired in a series-type connection, whichallows operation at larger voltages. However, the sequence connection is generally made with clamping diodes, which eliminatesovervoltage concerns.

Furthermore, thinking about the switches are nottruly sequence connected, their switching can be staggered, whichreduces the switching frequency and for this purpose the switching losses.However, the most currently usedinverter topologies, which are in the 41

III. MATLAB/SIMULINK RESULTS

Fig 4: Proposed IPQC with MLI.

Fig 5: proposed MLI system.

International Journal for Modern Trends in Science and Technology

Maddala Uadykiran and A Durga Prasad : Power Quality Improvement with Multilevel Inverter Based IPQC for Microgrid

Selected signal: 25 cycles. FFT window (in red): 2 cycles 20 10 0 -10 0

0.1

0.2

0.3

0.4

0.5

Time (s)

Fundamental (50Hz) = 6.941 , THD= 7.49%

Fig 6: load voltage response before and after MLI based IPQC operation.

Mag (% of Fundamental)

7 6 5 4 3 2 1 0

Selected signal: 25 cycles. FFT window (in red): 2 cycles

0

2000

400

4000 6000 Frequency (Hz)

8000

10000

200 0 -200 -400 0

0.1

0.2

0.3

0.4

0.5

(b) Fig 8: Current THD values without IPQC

Time (s)

Fundamental (50Hz) = 229.2 , THD= 18.76%

IV. CONCLUSION

Mag (% of Fundamental)

15

10

5

0

0

2000

4000 6000 Frequency (Hz)

8000

10000

(a) Selected signal: 25 cycles. FFT window (in red): 2 cycles 400 200 0 -200 -400 0

0.1

0.2

0.3

0.4

0.5

Time (s)

Fundamental (50Hz) = 460.7 , THD= 2.52%

Mag (% of Fundamental)

2.5 2 1.5 1 0.5 0

0

2000

4000 6000 Frequency (Hz)

8000

10000

(b) Fig 7: Current THD values without IPQC Selected signal: 25 cycles. FFT window (in red): 2 cycles 20 10 0 -10 0

0.1

0.2

0.3

0.4

0.5

Time (s)

Fundamental (50Hz) = 13.95 , THD= 1.76%

Mag (% of Fundamental)

3 2.5 2 1.5 1 0.5 0

0

2000

4000 6000 Frequency (Hz)

(a) 42

8000

10000

The cascaded electrical converter change indicators square measure generated victimisation triangular-sampling current day controller; it gives a dynamic typical overall performance under transient and regular u . s . a . conditions, doctorate analysis additionally inner the IEEE standards. quick real-power idea specially based} cascaded development electrical converter based totally definitely IPQC is linked within the distribution network at the PCC through filter inductances and operates in a very manage system. A cascaded construction voltage furnish electrical converter pretty especially primarily based IPQC victimisation quickly proper power controller is located to be a desirable choice for cable getting to know to compensate harmonics, reactive electricity and electricity trouble with the IRP controller reduces harmonics and offers reactive electrical energy compensation thanks to non-linear load currents; as a stop end result provide current(s) end up curving and crew spirit strength challenge is in addition executed below each transient and consistent state conditions.

This paper has conferred a unique variable reactor supported the magnetic flux management. A electrical machine with air gap is chosen, and therefore the coil modern of the electrical computing device is detected. A voltage-sourced electrical converter is utilized to comply with the first present day to provide each different current, that is injected to the secondary. as quickly as the injected present day is adjusted, the equal resistance of the first winding of the electrical system can modification incessantly. In phrases of the novel variable reactor, a special IPQC splendid for microgrid is projected. the first winding famous

International Journal for Modern Trends in Science and Technology

Maddala Uadykiran and A Durga Prasad : Power Quality Improvement with Multilevel Inverter Based IPQC for Microgrid

adjustable resistance, that performs the function of strength go with the flow management, fault present day electric circuit, and voltage compensation to elementary.

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International Journal for Modern Trends in Science and Technology