Research on Power System Harmonic Analysis Method of Improved Window Interpolation

The fast Fourier transform(FFT) has already become a main method of the electrical harmonic analysis since it's easily realized in embedded system,but there are difficulties in performing synchronized sampling and integral period truncation in the electric power harmonic analysis,and the accuracy of the analysis result would be disturbed by the frequency leakage.Some efforts had been made,such as the utilization of window functions and interpolation algorithms,to improve the accuracy of harmonic parameters computation by FFT.In this paper the causes of the frequency leakage of FFT is analysised,The sidelobe characteristic of convolution window and the double interpolation algorithm are both discussed,an approach for electrical harmonic analysis based on the convolution window double interpolation FFT was proposed..