Detection of voltage flicker based on hilbert transform and wavelet denoising

Abstract

Precise detection is very important for monitoring and controlling voltage flicker efficiently. As voltage flicker can be regarded as a narrowband signal, this paper proposed a novel detecting method based on Hilbert transform and wavelet denoising. By Hilbert transform, the flicker envelope can be extracted while higher harmonics and other noises contained in voltage flicker can be eliminated by Daubechles-8 wavelet. Simulation results showed that the higher harmonics and other noises could be filtered and amplitude and frequency of the modulation signal could be calculated precisely. Therefore, this detection method can be widely applied to developing intelligent and digital flickermeters. © 2008 DRPT.