Most suitable mother wavelet for measurement of power system harmonics using DWT in view of IEEE Standard 1459-2000

Fourier transform (FT) based techniques have been traditionally used for power system harmonics analysis. A recent alternative approach of wavelet transform (WT) is applied for non-sinusoidal signal analysis which has been found very useful in power quality studies. The problem of root mean square (RMS) value calculation is an important issue in harmonic analysis. This paper uses a statistical approach for RMS calculation. The proposed method simplifies wavelet based harmonic measurement process and increases measurement accuracy. Case studies from practical power systempsilas voltage and current signals are demonstrated. The measurement results using the discrete wavelet transform (DWT) method for various wavelet families are compared and discussed with the results of IEEE Std. 1459-2000 which forms the basis to propose the most suitable mother wavelet for power system harmonics analysis.