基于行波波形综合相似度比较的电缆故障选线  

Cable fault line selection based on comprehensive similarity comparison of traveling wave waveforms

作　　者：王雪菲 李京[1,2] 陈平 刘洋[1] 张文轩[1] 于毅 WANG Xuefei;LI Jing;CHEN Ping;LIU Yang;ZHANG Wenxuan;YU Yi(School of Electrical and Electronic Engineering,Shandong University of Technology,Zibo 255049,China;Shandong Kehui Power Automation Co.,Ltd.,Zibo 255087,China)

机构地区：[1]山东理工大学电气与电子工程学院,山东淄博255049 [2]山东科汇电力自动化股份有限公司,山东淄博255087

出　　处：《电力系统保护与控制》2022年第1期51-59,共9页Power System Protection and Control

基　　金：国家重点研发计划项目资助(2017YFB0902800);国家电网公司科技项目资助(52094017003D)。

摘　　要：针对现有小电流接地故障行波选线方法高度依赖行波初始波头的不足,通过分析三芯电缆故障行波折、反射过程,提出了基于行波电流波形综合相似度比较的小电流接地系统电缆故障选线方法。该方法首先利用S变换提取电缆故障产生的金属护层接地线行波电流时频信息,然后构造行波电流信号的时频能量矩阵和波形相似度矩阵,进而根据波形相似度矩阵计算每条线路和其他线路的行波波形综合相似度系数,最后通过比较波形综合相似度系数实现故障选线。仿真和实测数据分析表明,所提出的方法可以充分利用暂态行波故障信息,且不受系统中性点接地方式、故障位置、过渡电阻等因素影响,选线结果准确、可靠。Existing traveling wave fault line selection methods for a small current grounding system highly rely on the initial head of the traveling wave. To help overcome this deficiency, this paper proposes a fault line selection method based on the comparison of comprehensive similarity of traveling wave current waveforms for a small current grounding system by analyzing the refraction and reflection process of the fault traveling wave in three-core cable. First, it extracts the time-frequency information of the traveling wave current caused by cable faults in metal sheath grounding wire by S-transform, then constructs the time-frequency energy matrix and waveform similarity matrix of the traveling wave current signal. It then calculates the comprehensive similarity coefficient of traveling wave shape of each line with other lines according to the waveform similarity matrix. Finally, it accomplishes the fault line selection by comparing the comprehensive similarity coefficient. Simulation and measured data analysis shows that the proposed method can make full use of the transient traveling wave fault information, and is not affected by the neutral point grounding mode, fault location and transition resistance of the system, and the line selection results are accurate and reliable.

关 键 词：三芯电缆 金属护层 行波 波形相似度 故障选线 

分 类 号：TM75[电气工程—电力系统及自动化] TM862