A laboratory for time-frequency analysis of power quality disturbances using wavelets

This paper presents a laboratory for time-frequency analysis of power quality disturbances using wavelets. Wavelet-packet transform is applied to simulated or real disturbance records previously recorded by power quality monitoring equipment using different mother wavelet function, sampling frequency and different wavelet decomposition trees, computing the magnitude, mean and standard deviation, number of peaks, energy or entropy of the output coefficients at different resolution levels for extraction of the distinctive features of power quality disturbances.