Block Theresholding Spatial Combined De-noising Method for Suppress White-noise Interference in PD Signals
Xishan Wen · Gao dianya jishu · 2011
As white noise interference inevitably exists in gas insulated switchgear(GIS) partial discharge(PD) detection,the available suppression methods are unsatisfactory.According to the feature of white-noise,we propose a new de-noising method based on wavelet transform,namely,the block threshold spatial combined de-noising method.First,this method adopts threshold de-noising to preprocess the sub-band signal of wavelet decomposition of noise,then the spatial correlation method for data processing is executed,finally,the results are reconstruct and return to the original signal.This method combines the advantages of threshold de-noising method and spatial correlation method.Moreover,we discuss the impacts of decomposition level,noise intensity,and iterations of spatial correlation algorithm on de-noising effect by analyzing simulation and experiment,and obtain the optimal parameters.Compared with de-noised effect of complex multilevel threshold,the de-noised results of field monitoring signal manifest that this method has better de-noising effect and less energy loss,and it is conducive to restore the PD signal.