Some observations on selection of most suitable mother wavelet for measurement of power system harmonics using CWT

In the literature, wavelet techniques are proposed for the power quality analysis of power systems. The choice of most suitable mother wavelet, which is a key to any meaningful wavelet analysis, depends on the application and no general rule exists for the selection. This paper demonstrates the selection of an appropriate mother wavelet for power system harmonic analysis. Different mother wavelets i.e., Gaussian, Morlet, Shannon, and complex wavelet, have been used for this analysis. The measurement results using the continuous wavelet transform (CWT) method for various mother wavelets are compared and discussed with the results of IEEE standard 1459-2000, which forms the basis to propose the most suitable mother wavelet for power system harmonics analysis. Appropriateness of Gaussian wavelet as most suitable mother wavelet is supported with two performance metrics, viz. minimum percentage error with respect to IEEE Std. 1459-2000 based values and lowest root mean square error (RMSE) value in comparison to other mother wavelets.