An Improved Method for Power Harmonic Analysis Based on Blackman Window and Phase Difference Correction

Abstract

It is difficult to make the realization of synchronous sampling and the whole cycle truncation when we use the fast Fourier transform (FFT) for power system harmonic analysis .Once the FFT is used, the spectral leakage caused by it will affect the accuracy. Using Blackman window weighted to the harmonic signal, combined with the spectrum analysis of phase, An improved method for power harmonic analysis based on Blackman window and phase shifted difference correction is presented in this paper. The calculation equation of multiple fundamental harmonic signal frequency, amplitude and initial phase angle is derived and the conventional spectral phase correction method is improved. The simulation results show that the calculation accuracy using Blackman window phase correction signal harmonic analysis is improved significantly compared to Hanning window interpolation, Blackman window interpolation and Hanning window phase difference. The algorithm is simple, and has high precision and versatility, which can be applied to high-precision power metering and power quality analysis.