Measurement of Harmonics in Power Systems Using Near Perfect Reconstruction Filter Banks

In this letter, the use of near perfect reconstruction filter banks on the harmonic analysis of power system waveforms is investigated. For this aim, wavelet packet transform for the rms measurement is implemented. Besides commonly used wavelet filters, the influence of several of Johnston´s filters is examined. Experimental tests are performed under different conditions in case of stationary and nonstationary signals. The obtained results show that Johnston filters outperform the commonly used wavelet filters for harmonic analysis.