【摘要】 研究了绝缘子污秽放电声发射监测中用小波变换进行信号提纯与消噪的实现问题。在大量绝缘子污秽放电声发射试验基础上,分析总结了污秽放电声发射信号的共有特点。并提出一种基于声发射信号小波变换的小波基选取方法。采用选取的最优小波函数rbio3.9对声发射信号进行频谱分析,提取了声信号的特征频带,并对重构后的信号进行二重小波分解消噪。两组声发射信号的小波变换消噪结果表明,小波变换提高了信号信噪分离结果的可靠性,有效地降低了噪声对污秽放电声发射信号的影响。更多还原

【Abstract】 This paper studies how to use wavelet transform method to purify and denoise in acoustic emission monitoring of polluted insulator discharge.Based on numerous acoustic emission experiments of polluted insulators discharge,the common characteristics of acoustic emission wave emitted from polluted insulators discharge are summarized.And an effective method to select best wavelet basis is proposed based on wavelet transform of acoustic emission signals.Then the appropriate wavelet function is chosen.And frequency analysis of acoustic emission signals is realized using wavelet transform with optimal wavelet function of rbio3.9.Characteristic frequency bands are extracted to reconstruct the signal,and then duplicate wavelet decomposition is applied to reduce noise of reconstructed signal.Two examples using wavelet analysis to denoise in acoustic emission signals are given.Experimental result shows that the reliability of separating the signal from noise is improved and noise influence on acoustic emission signal is reduced effectively after using wavelet transform method.更多还原