摘要
基于超高频包络检波的GIS局部放电检测系统采样得到的超高频局部放电包络信号中含有噪声。笔者分析了检测系统测量过程中可能混入的几种噪声,通过截取没有局部放电的采样信号进行频谱计算,理论与实测分析结果均表明,包络检波后信号中的噪声主要是白噪声。基于小波变换的滤波算法对白噪声有很好的抑制效果,文中在对小波变换原理进行简要分析的基础上,提出了改进阈值的小波滤波算法,仿真及实测信号的滤波结果证实了该改进算法的有效性。
The envelope signal, detected by the GIS partial discharge detection system based on ultra-high qrequency envelope detection, contains noise and interference. This paper analyzes the sources of interferences, and calculates the spectrum of a section of experimental signal. The analysis of theoretical and practical signals show that the noise in envelope signal is mainly white noise. The filtering algorithm using wavelet analysis and transform is effective for denoising the white noise. An improved threshold method of denoising with wavelet is presented based on the analysis of the principle of wavelet transform, and the denoising results of simulated and practical signals verify its effectiveness.
出处
《高压电器》
CAS
CSCD
北大核心
2009年第1期33-35,共3页
High Voltage Apparatus
关键词
超高频
包络检波
小波变换
阈值
ultra-high frequency
envelop detection
wavelet transform
threshold
