Power Quality: A Growing Concern

The power grid is being forced to change as the result of not one but many simultaneous developments. These include the growing need to connect green energy sources, such as wind and solar power, and the steady reduction in the number of traditional bulk generation plants that rely on fossil fuels as their energy source... - Andrew Sagl

The modern power distribution grid is changing rapidly and these changes can be expected to have an impact on power quality, which is the concept of powering sensitive equipment in a manner that is suitable to the operation of that equipment. In the short term at least, the impact is likely to be negative, with power quality problems becoming more rather than less troublesome.

The power grid is being forced to change as the result of not one but many simultaneous developments. These include the growing need to connect green energy sources, such as wind and solar power, and the steady reduction in the number of traditional bulk generation plants that rely on fossil fuels as their energy source. Loads on the grid are also changing, with new technologies like electric vehicles leading to an even greater demand for power and a shift in the hours of peak demand. To help address these changes, smart-grid technology, designed to make the grid more efficient and more flexible, is being introduced.

It might be tempting to think that the spread of smart-grid technology will alleviate power quality problems, with a consequent reduction in the need for power quality investigations. Unfortunately, this isn’t the case. A primary objective of the smart grid is to increase the reliability of power delivery – it is unlikely to have any significant impact on the quality of the power being delivered. In fact, the new types of loads and sources continually being added to the grid will inevitably create new power quality challenges.

Some of the most common power system fluctuations impacting power quality include under- and over-voltage, dips (sags) and swells, transients, unbalance, flicker, harmonics and rapid voltage changes. To help readers refresh their understanding of power quality and to stay up to date with the latest thinking, we are currently preparing a series of articles, starting with the fundamentals of PQ and progressing to topics such as what is a Class A recording, transient and harmonic impacts on motors & transformers, energy fundamentals, and the truth about energy saving devices. The first of these timely and well informed series of articles will appear in the next edition of Electrical Tester and will look at the foregoing types of power system fluctuations, explaining why and how they occur, examining the effects they have on the power distribution network and on loads, and discussing how they can be measured and evaluated.

Megger has been working extensively to address these concerns and with its latest innovation – MPQ1000 and MPQ2000.

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The MPQ1000 is in compliance with IEC61000-4-30 Class A and is rated CATIV at 600V. It can be used for a wide variety of applications including substation monitoring, equipment and breaker tripping, load studies and load balancing as well as for switchgear and component failure.

This highly intuitive unit delivers unmatched capability in a smart ergonomic platform. In both the scope and DVM modes, the versatile MPQ1000 can record power, energy, RMS, sags, swells, transients down to 1 microsecond, harmonics, inter-harmonics, harmonic direction, THD, TDD, flicker, unbalance, rapid voltage change (RVC), mains signalling, phase angle deviation, as well as performs waveform analysis to the 128th harmonic in real time.

Data gathered during testing can be recorded with the MPQ1000 record verification by simply pushing a button. This feature automatically detects the current clamps, recognises its range, identifies the nominal voltage and sets the triggers, as well as verifies that the unit is connected properly to what it is testing.

The MPQ1000 unit also features flexible current clamps that have four selectable ranges from 0 to 6000A.

The MPQ2000 Megger Portable Power Quality Analyzer, with its latest software and enhanced capabilities, addresses the international IEC61000, IEEE1159, IEEE519 and EN50160 series of power quality and delivery standards used around the world. Powered off of either the phase A voltage input or an auxiliary input that operates off of 115 V 60 Hz or 230 V 50 Hz makes the unit highly versatile, allowing it to be used in any location. Additionally, the MPQ2000 measures ac and dc simultaneously up to 1000V.

The MPQ2000 is an easy-to-use advanced portable 3-phase power analyzer housed in a ruggedized weatherproof enclosure. It comes with a field-replaceable, rechargeable battery with backup/ride-through time up to 5 hours, making the MPQ2000 the ideal tool for outdoor use. The unit can be left at remote locations and data can be viewed from the user’s locations at the convenience of the user.

The analyzer comes equipped with self-identifying, four range flexible current clamps which are powered by the unit. No batteries are required. Additionally, the analyzer comes equipped with real-time scope and DVM modes. View RMS data, wareforms, demand data, phase angles, vector diagrams, harmonics, inter-harmonics, unbalance, flicker, and more in real time.

When data needs to be recorded, the MPQ2000 record-verification feature automatically identifies the current clamps being used, recognises the range they are in, and verifies the unit is connected properly. The analyzer verifies that all voltage and current connections are correct prior to the start of the recording. This eliminates the possibility of the recording of ‘bad’ data.

From utilities, to commercial and industrial, to residential monitoring, the MPQ2000 is your comprehensive intuitive tool for analyzing and solving power quantity and power quality problems.

Megger is one of the world’s leading manufacturers and suppliers of electrical test and measurement equipment. With research, engineering and manufacturing facilities in the USA, UK, Germany, and Sweden, combined with sales and technical support in most countries, Megger is uniquely placed to meet the needs of its customers worldwide.

For more information, please visit megger.com

Andrew Sagl
Product Manager
Power Quality, Megger US

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