A two-stage method for harmonic measurement using the wavelet-packet transform

This paper proposes a new method, based on the use of the wavelet-packet transform, for the characterization of harmonics in power supply systems. The method proposed, which is compatible with standard IEC 61000-4-7, consists of a two-stage process. In the first stage the fundamental component of the input signal is computed and subtracted from the input signal and, in the second stage the wavelet-packet transform is applied to the resultant signal to compute the rest of harmonic groups in the input signal without the interference of the fundamental component spectral leakage. The results obtained in the application of the method show a good performance in the estimation of the harmonic groups in voltage and current waveforms