【摘要】 局部放电检测系统由于覆盖了比较宽的频带,采集到的信号中会不可避免地包括背景噪声或干扰信号,针对局部放电检测中比较严重的周期性窄带干扰信号,介绍了现有的抑制此类干扰的方法,研究了基于db4小波基的软阈值小波包变换去除周期性窄带干扰的方法,在实验室环境下,对交联聚乙烯(XLPE)电缆的局部放电进行检测,用小波包变换去除所采集波形的周期性窄带干扰,由试验结果可以得出小波包变换抑制周期性窄带干扰效果良好.更多还原

【Abstract】 There are background noises and interferences in the signal acquired,due to partial discharge(PD) detection system covers a broad frequency band.To suppress periodic narrowband signal which is a quite serious interference in PD measurement,the existing suppression method is introduced,the new method of wavelet packet transform is mainly studied to de-noise the periodic narrowband in XLPE cable PD detection system,which is based on the db4 basic wavelet using soft threshold.The results of the experiment show that wavelet packet transform is effective in restraining the periodic narrowband interferences to extract the PD pulses in XLPE cable PD monitoring system.更多还原