Harmonic Analysis Via Wavelet Packet Decomposition Using Special Elliptic Half-Band Filters

The fast Fourier transform (FFT) is the most widely used power system harmonic analysis tool in real-time power metering due to its computational efficiency. Recently, an alternate method, i.e., wavelet packet decomposition (WPD), has been applied to power system signals to meter the voltage and current harmonics. Although the new method provides better analysis, the computational complexity of WPD places a limitation on its use in real-time metering. This paper proposes the use of all-pass-implemented special half-band elliptic infinite-impulse-response filters in the WPD of power system signals. The proposed implementation reduces the computational complexity to levels comparable to FFT.