An Improved Half-wave Symmetric FFT Algorithm for Grid Harmonics Analysis

A improved FFT algorithm considering the half-wave symmetric characteristic of power system signals is presented based on the fast Fourier transform (FFT) method. The half-wave symmetric FFT algorithm could omit the even harmonics in its calculation for the half-wave symmetric signals with only odd harmonics. So the computation of the improved FFT just has a half amount of the traditional FFT. It could save a lot of calculation time. The algorithm formulation is deduced and the entire computation process is designed. Experiment results validated the feasibility.