Voltage Flicker Detecting Based on Improved HHT

Abstract

Abstract: This paper puts forward a new method based on Hilbert-Huang Transform (HHT) and Wavelet denoising for extracting feature information of voltage flicker signal. Firstly, envelope signal could be extracted by using HHT from original signal containing noises. Then the noises and higher harmonic components of envelope signal could be removed by using Wavelet denoising. Finally, the noise-removing envelope signal could be decomposed by using Empirical Mode Decomposition (EMD) for getting accurate amplitude modulation wave. The new method was applied to virtual instrument by using the MATLAB script node in LabVIEW. Experimental results show that this new method is applicable for analyzing voltage flicker signal both in time domain and frequency domain. The accurate time, amplitude and frequency of voltage flicker signal which is mutational and non-stationary can be obtained by using this new method.