Research On Power Quality Analytical Method Based On Fuzzy Theory And Wavelet Transform

Power quality analytical methods which take the de-noising methods as the major content are researched in this paper. Three kinds of power quality de-noising methods are proposed and examined by emulational experiments. The changing windows de-noising method based on fuzzy theory use membership to choose the template. The advantages of this method are not marked, and the method needs to be improved. The de-noising method based on triangle module operator takes full advantages of fuzzy theory and the information fusion technology. The membership is fused by triangle module operator. The ability of de-noising and keeping break-points'information are primely enhanced. The de-noising method based on Gaussian filter uses the Gaussian theory, and the convolution is carried out between part addition template and signals. Differential coefficients are used to adjust measure parameter and the addition coefficient of filter. The effect of this method is well, and it exploites the theory view of power quality analysis.Wavelet transformation is broadly used for power quality analysis. By analysis and experiments, during all of the threshold de-noising methods based on wavelet transformation, the most suitable method for power quality de-noising is chosen, it is the hard threshold de-noising method based on Universal-threshold regular.