中文摘要：

在电力系统电能质量信号的检测中,不可避免会遇到因为测量设备故障以及环境因素的影响,使得信号夹杂噪声,使得采集到的信号受到一定程度的噪声污染,干扰了检测电力系统的电能质量准确性,而小波降噪在信号降噪中具有很大优势,所以利用小波降噪降低电力系统信号中的噪声具有重要的意义。在比较分析小波变换的优势,多次进行小波变换反馈信号特征,通过观察信号的时频特性,应用小波变换局部化特性可调整不同叠加信号的系数,可最大限度的得到电能质量的有用的分析信号,然后再分析和运用多种阈值处理方式改进小波降噪,并应用差值的方法分析哪种阈值处理方式更加有效。

英文摘要：

Measurement equipment failure and environmental factors often generate noise in the detection of electric power system. Therefore,the signals which we collected suffer from a certain degree of noise pollution. It reduces power quality of electric power system,and wavelet transform can lead to a great benefit in signal de-noise. Hence,it has great significance for electric signal denoising to make use of wavelet transform. The purpose of this paper is to comparatively analyze the advantage of wavelet transform,conduct several times primary wavelet transform and couple back problems in electric power system detection. after that,the improvement of wavelet de-noising is conducted by subprime wavelet transform,and multiple threshold processing method is also analyzed and utilized.