The Study on FFT Harmonic Detecting Method of Rural Network Based on Wavelet Denoising

The veracity of harmonic detection directly affect the evolution of harmonic pollution status of power network and the implementation of suppression measures, using wavelet soft-threshold denoising to reduce the noises in the noised power harmonic signals, and then using fast Fourier transform to analysis the signal which has been reduced noises, extracting the harmonic current and total harmonics distortion. In the Matlab simulation environment testing, results show that the detecting harmonic ratio after wavelet denoising is closer to pure signal harmonic ratio, denoising method improves the veracity of harmonic signal detection, this method base on FFT and wavelet de-noising for harmonic detection is suitable for the application of harmonic detection systems and devices.