Wavelet Transform Algorithms in Analyzing Transient Phenomena and Power Quality Parameters

The article presents analysis technique for power quality parameters and transient switching processes with the help of wavelet transformation. Recommendations have been given on the choice of the optimal mother wavelet function. The criterion takes into account the power spectrum of the range covered. The second condition of the suggested criterion is that root-mean-square deviation of the initial and reconfigurable signal should tend to zero due to wavelet transform. Switching processes in capacitor banks and power lags have been studied. The authors compare 5 mother wavelets basing on the suggested criterion. Wavelet db10 has minimum mean square deviation at signal restoration. An opportunity to apply detailizing wavelet coefficients responsible for localization of high-frequency components, to identify changes in operating parameters of the power system has been described. Increase in amplitudes of detailizing coefficients is connected with discontinuity of higher derivatives, when operating parameters change. A numerical experiment to determine operating values of higher harmonics currents has been given.