基于输入阻抗谱的电缆故障类型识别及定位  

Identification and Location of Cable Faults Based on Input Impedance Spectrum

作　　者：李蓉[1] 周凯[1] 饶显杰 谢敏 梁钟颖 龚薇[1] LI Rong;ZHOU Kai;RAO Xianjie;XIE Min;LIANG Zhongying;GONG Wei(College of Electrical Engineering,Sichuan University,Chengdu 610065,China;State Grid Wuxi Power Supply Company,Wuxi 214000,China)

机构地区：[1]四川大学电气工程学院,成都610065 [2]国家电网无锡供电公司,无锡214000

出　　处：《高电压技术》2021年第9期3236-3245,共10页High Voltage Engineering

基　　金：国家自然科学基金(51877142)。

摘　　要：为解决脉冲电流测试法(impulse current experimentation,ICE)与时域反射法(time domain reflectometry,TDR)对电力电缆故障进行诊断时存在的不足,提出一种基于输入阻抗谱的电缆故障类型识别及定位方法。首先,依据电力电缆分布参数模型、输入阻抗谱、频谱分析、Kaiser窗,阐明电力电缆故障类型识别及定位的基本原理。然后,对不同类型的电缆故障(开路、短路、高阻、低阻故障)进行建模分析,通过仿真获取正常/故障电缆的输入阻抗谱特征。基于此,再对故障电缆的输入阻抗谱进行处理,得到具有直观性的故障定位谱图,实现对电缆故障的高灵敏度定位。最后,在实验室40 m长的同轴电缆和1 000 m长的10 kV交联聚乙烯(cross-linked polyethylene,XLPE)电力电缆上进行模拟故障测试,检验该方法对电缆故障的诊断效果并验证所提故障类型识别判据的有效性。仿真和实验结果表明:该方法对开路故障及阻抗在0?~38Z0 (Z0为电缆的特性阻抗)范围内的故障点具有较好识别效果,故障定位误差<0.4%。与ICE法、TDR法相比,该方法的测试灵敏度更高,可实现对电缆故障的类型识别与高精度定位。In order to solve the shortcomings of impulse current experimentation(ICE) and time domain reflectometry(TDR) in the diagnosis of power cable faults, a method based on input impedance spectrum is proposed for identifying and locating cable faults. First, according to the distribution parameter model of power cables, input impedance spectrum,spectrum analysis, and Kaiser window, the basic principles were explained in detail. Then, different types of cable faults(open-circuit, short-circuit, high-resistance and low-resistance faults) were modeled and analyzed. And the input impedance spectrum characteristics of normal/fault cables were obtained by simulation. Based on this, the input impedance spectra of the faulty cables were analyzed to obtain an intuitive fault location spectrum, thereby achieving high-sensitivity location of cable faults. Finally, to test the effectiveness of the method, fault simulations were carried out on the 40 m-long coaxial cable and the 1 000 m-long 10 kV cross linked polyethylene(XLPE) power cable in the laboratory. The simulation and test results indicate that the method has a good recognition effect for the open-circuit fault and fault points with impedance in the range of 0 ? ~ 38 Z0(Z0 is the characteristic impedance of the cable), and the fault location error is less than 0.4%. Compared with ICE method and TDR method, this method is more sensitive, which can be adopted to realize the type identification and high-precision positioning of cable faults.

关 键 词：输入阻抗谱 电缆故障 故障类型识别 故障定位 KAISER窗 

分 类 号：TM75[电气工程—电力系统及自动化]