FFT Algorithm with High Accuracy for Harmonic Analysis in Power System

Abstract

The Fast Fourier Transform(FFT) cannot be directly used to the harmonic analysis of electric power system because of its higher error,especially the phase error when used with a sample sequence which is not synchronized with the signal.To reduce the influence of an unsynchronized sample sequence on FFT and to improve the precision of harmonics in electric power system,this paper improves the algorithm by using windows and interpolation methods.The paper firstly addressed the leakage and picket fence effects of FFT briefly and then analyzes the interpolation algorithm on Rife Vincent(I) window in detail.Besides,the computing formula for the harmonic parameter estimation are given as well.The simulating result demonstrates that the improved algorithm holds a very high precision wien used for the unsynchronized sample sequence.