Denoising Analysis Of Power Quality Transient Signal Based On Wavelet Analysis

In recent years,depending on the electric furnace steelmaking,silicon controlled rectifier,washing machine,air conditioner and more and more electric equipment widely used,the nonlinear,fluctuating and impact load have been increased.It deteriorated the power quality,and distorted the voltage and current waveform.These precise control devices such as computer,microprocessor power electronic control system,modern industrial and civil electric equipment and so on,are more susceptible to power quality disturbance signals.In order to realize the power quality signal denoising,the purpose of accurately detecting the power quality signal should be achieved.We can use method of wavelet analysis to simulate the transient signal of power quality,then the power quality transient signal denoising have been findished by using Fourier transform denoising,wavelet transform denoising,wavelet packet analysis denoising and EMD denoising method.Whether the experimental wavelet transform can achieve better denoising effect.Job content(1)The selection of wavelet bases has been studied.The comparison between the properties of the existing wavelet bases,scale functions and wavelet functions has been made and concluded.(2)The power quality transient signal denoising have been findished by using Fourier transform denoising,wavelet transform denoising,wavelet packet analysis denoising and EMD denoising method.By comparing the image,singnal-to-noise ratio and mean square error,we can know the optimal denoising method.With the expansion of wavelet bases selection method and four kinds of denoising method in power quality transient signal analysis,the completion of the work carried out in this paper.It is found that we can achieve better denoising result through a series of analysis and selection in this way.And efforts to combine the results with our own work,in order to control and improve the quality of power.