On the Implementation of Time-frequency Transforms for Defining Power Components in Non-sinusoidal Situations: A Survey

ISSN： 1532-5016

Source： Electric Power Components and Systems, Vol.37, Iss.4, 2009-04, pp. : 373-392

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Abstract

Power quality indices play an important role in decision making in deregulated competitive environments. Useful power quality indices require clear and accepted definitions of power components as well as the RMS values of voltage and current. This is especially true in case of non-stationary distorted waveforms, where neither a frequency-domain-based approach using fast Fourier transform tools nor a time-domain-based approach using real-time data give satisfactory results. Wavelet transform is able to represent any distorted waveform in a time-frequency spectrum while preserving relevant information in both time and frequency domains. Different methods have been proposed in an attempt to define power components in the wavelet domain. This article offers a critical evaluation of the current state-of-the-art concerning this topic. The article also offers conclusions and suggested future work.