基于小波变换的导线绝缘故障定位方法  

Method of Wire Insulation Fault Location Based on Wavelet Transform

作　　者：张俊民[1] 周小猛[1] 魏娟[1] 曹大树 姚红宇[2] 

机构地区：[1]北京航空航天大学自动化科学与电气工程学院,北京100191 [2]中国民用航空总局航空安全技术中心,北京100028

出　　处：《电工技术学报》2012年第5期99-104,共6页Transactions of China Electrotechnical Society

基　　金：民航安全技术分析和鉴定实验室开放研究基金资助项目(200603)

摘　　要：基于时域反射法(TDR)建立了航空导线绝缘故障的数学模型,仿真研究了不同上升时间的阶跃波在有损耗故障导线中传播的规律,结果表明陡峭上升沿的入射波有利于发现小范围的绝缘故障,同时高频信号的传播损耗使得反射波形变得平滑,给故障处尖峰起始点的定位带来误差。搭建了TDR试验平台,检测小尺寸的导线绝缘故障,对接收到的信号运用小波软阈值去噪法消除噪声,再进行连续小波变换确定故障处尖峰的起始点。实验结果表明,小波方法有助于发现较小的故障,并提高故障定位的精度。能检测到的绝缘故障最小长度为5cm,定位误差小于2%。A mathematical model of aerospace wire insulation faults is presented based on time domain reflectometry （TDR） in this article. Transmission in a defective lossy is simulated for step wave of different rise time. The results show that steep leading edge of incident signal is conducive to find out small insulation faults, and simultaneous attenuation of high frequency signals results in smooth reflected wave, which leads to errors in locating the starting point of peaks corresponded to faults. A TDR test platform is built to detect small insulation faults. Soft threshold de-noising method of wavelet is used to eliminate noise in received signals, and then the starting point of peaks corresponded to faults is ascertained by continuous wavelet transform. Test results indicate that wavelet method helps to identify failure points, and to improve the accuracy of faults location. Minimum length of faults found in experiment is 5cm and positioning error is less than 2%.

关 键 词：时域反射法 航空导线 绝缘故障检测 小波 

分 类 号：TM246[一般工业技术—材料科学与工程]