Power Quality Analyzer PQM-707 The dynamic development of electronics contributes to the emergence of newer and newer technologies that enable the production of goods in a fast, efficient and cheap manner. We have devices that help us in everyday life, at work, bring entertainment and allow us to control and communicate with them. We are at a stage of technological development in which it becomes normal that the devices control themselves by sending only data to the supervisor. The common denominator for this area of human activity is electricity. It turns out that progress has basically made humanity completely dependent on electricity in less than 100 years! Everyone is used to saying that electricity or voltage is as common and obvious as the air we breathe. As long as the electrical devices drew their energy linearly, there were no major problems. Progress, miniaturization and automation made it necessary to build new, impulse powered systems. Compact light sources, devices controlling technological processes, welding machines, and even an ordinary electric kettle or induction hob cause harmful current and voltage distortions, which causes energy losses and damages to electrical devices. It particularly affects industrial plants, where production stoppage causes huge losses. Power quality is a relatively new concept. Many people working in maintenance services take it for granted. There is energy - there is quality. Many more think of it as magic and blame all troubles on harmonics, whatever they are. There are many reasons for this. One of them is the complexity of the problem. Another is the level of complexity of measuring devices that cannot be operated without a specialistic knowledge. Electricity is a commodity and it is more and more commonly monitored in order to check whether its parameters comply with the requirements contained in regulations and standards. Unfortunately, this is not enough. Maintenance services struggle with many problems causing various types of damage to power electronic devices or drives, which are caused by fast-changing phenomena. Therefore, the power quality may comply with the requirements (because measured values are averaged) and despite this fact, we are still exposed to failures of electrical devices, and thus financial losses. The solution to these problems may be the dissemination of testing power parameters, not so much in terms of its quality, but also in terms of harmful phenomena causing damage to machines and devices, as well as its quality. For this purpose, SONEL S.A. constructed a power quality analyzer PQM-707. It is an autonomous device that can be widely used in all places that require ad hoc control of phenomena occurring in electrical systems. These can be hospitals, furniture factories, assembly plants, service facilities, server rooms, etc. Of course, long-term registration and power quality testing for compliance with norms is also possible.
Fig. 1. Power quality analyzer PQM-707 in live mode
The analyzer is designed, that it can be used in a comfortable, ergonomic and possibly easy way. The large, clear 7� touch screen allows, immediately after connecting the device, live readings of basic information about the tested power network. Checking the battery for reactive power compensation or detecting the phenomena of higher harmonics, dangerous to drives will not be a
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problem anymore. Ease of use and intuitiveness make this device one of the first analyzers of this type for widespread use by electro-energy and maintenance services. The PQM-707 is designed in accordance with the S class of IEC 61000-4-30 standard. Four current inputs enable the connection of probes measuring current in three phases and in the neutral wire. Five voltage inputs enable voltage testing in all configurations, for any type of network, also between N and PE conductors. The entire operation of the analyzer takes place via the interface displayed on the touch screen. The configuration of the device is extremely simple and consists only in indicating and setting the appropriate parameters depending on the purpose of the test. You can also use ready-made settings for data registration in terms of parameter assessment for compliance with regulations of many European countries, Russia and Australia. All data is saved on the SD card. Taking into account the experience and comments gained from the market, the meter has been introduced with a sleep mode possibility. This contributes to a significant battery saving when we temporarily do not want to use the meter, e.g. while moving around the plant, but we also do not want to wait for the computer to restart after completely turning off the power.
Fig. 2. Using the PQM-707
For power quality regulations’ compliance testing, you can generate a report directly on the meter and it will be saved to memory. The report can be transferred to a USB flash drive and immediately handed over to the person interested or responsible for a given area at the place of the test. There is also a feature that allows to snap images from the display when you want to save waveforms or displayed data of live readings. The software is adapted to analyze the recorded data directly in the PQM-707. It gives great comfort of work and shortens the time of research and preparation of conclusions.
Fig. 3. Examples of PQM-707 live mode screens. Phasor diagram (left) and currents and voltages waveforms (right).
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The PQM-707 analyzer features a number of special functions dedicated to number of applications, including: Testing of the inrush current waveform, allowing to diagnose the causes of e.g. overcurrent protection or voltage dips at the start of motors. Investigation of the efficiency of the inverter, allowing to determine the degree of efficiency of the transformation of power on the direct side into power on the alternating side, e.g. in photovoltaic installations. Calculations of energy losses, allowing you to easily estimate the expected costs due to poor power quality. Calculation of energy costs according to the scheme set by the user for the zone or 24h tariff.
Fig. 4. Graph of the inrush current oscillograms
Fig. 6. Energy tariff setting
Fig. 5. Live mode readings of the inverter efficiency
Fig. 7. Energy cost calculator
To analyze data acquired during the recording process in a comfortable way, on a PC computer, free Sonel Analysis software is available. It allows viewing the measurement data in the form of tables, viewing the events with their oscillograms, creating reports for compliance with applicable regulations, and making various types of diagrams: values in time, harmonic distributions, current and voltage oscillograms, CBEMA and ANSI curves, or diagrams of event types compared to their duration. The software enables data export in TXT, CSV or HTML files as well as creating different reports, either on standard compliance, or user defined. The PQM-707 is very modern device, with the user interface as easy as possible, with full flexibility in configuring the meter, with intuitive operation. The software installed on the PQM-707 helps efficiently carry out both short-time tests and power quality recordings lasting 7 days (or longer). Comparing the recorded parameters at the test site has a significant impact on the speed and comfort of work, as a potential problem can be identified immediately. These features make the PQM-707 analyzer a widely used diagnostic tool on a larger scale.
SONEL S.A.
SONEL S.A.
www.sonel.com