A novel interpolated FFT algorithm based on convolution window

FFT algorithm is widely used in power system harmonic analysis. But in traditional FFT, big harmonic measurement error appeared caused by spectral leakage & hurdle effect while unsynchronized sampling. In this paper, an improved algorithm is introduced, a FFT with convolution windows and interpolated value is proposed to improve measuring accuracy of frequency, harmonic phase and amplitude through additional windows & interpolated corrective value. Guyuan Power Grid parameters of Ningxia Province were used into simulation analysis, the verification between simulation results and actual test reports show that: improved algorithm effectively enhance the accuracy of harmonic measurement with very limited spectral leakages and hurdle effects, and meanwhile simplified the whole operation.