Power Quality (PQ) Compression Algorithm - responsible electricity

By Y Harary, Elspec


Published in:

Electricity+Control, April 2014 (pages 32)

Enquiries: wayne@impactenergy.co.za


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The idea of Power Quality (PQ) compression algorithm (similar to the lossy compression method) that enables meters to continuously store the waveform of one or more power signals, regardless whether or not an event of interest was identified. This algorithm, referred to as PQZip, empowers a processor with a memory that is sufficient enough to store the waveform, under normal power conditions, over a long period of time - at least a month, two months or even a year.

The compression is performed in real time, as the signals are acquired; it calculates a compression decision before all the compressed data is received. For instance, should one parameter remain constant, and various others fluctuate, the compression decision retains only what is relevant from the constant data, and retains all the fluctuation data. It then decomposes the waveform of the power signal of numerous components, over various periods of the waveform.

It concludes the process by compressing the values of at least some of these components over different periods, separately. This real time Power Quality (PQ) compression algorithm, performed independent of the sampling, prevents data gaps and has a typical 1000:1 compression ratio.


Take note

  • It is essential to monitor the Power Quality (PQ) of electric signals at different locations along the electrical power network.
  • Electrical utilities monitor Power Quality (PQ) and currents at various network locations.
  • Power Quality (PQ) monitoring is particularly critical at sites where there is risk to people and the environment.