信号注入法在中压电缆绝缘在线监测中的应用  

Application of Signal Injection Method in on-line Insulation Monitoring

作　　者：奚航 周凯[1] 曾琴 饶显杰 刘力[1] 黄永禄 XI Hang;ZHOU Kai;ZENG Qin;RAO Xianjie;LIU Li;HUANG Yonglu(School of Electrical Engineering,Sichuan University,Chengdu 610065,Sichuan Province,China;Southeast Electric Power Design Institute Co.,Ltd.,China Power Engineering Consulting Group,Chengdu 610021,Sichuan Province,China)

机构地区：[1]四川大学电气工程学院,四川省成都市610065 [2]中国电力工程顾问集团西南电力设计院有限公司,四川省成都市610021

出　　处：《电网技术》2021年第1期409-416,共8页Power System Technology

基　　金：中国博士后科学基金项目(2015T90976)。

摘　　要：为了提高电力系统运行的可靠性,实现电缆绝缘的在线监测以替代传统的停电定期检修是其发展的必然趋势。已有的在线监测方法都有一定的局限性,因此在已有研究的基础上提出结合信号注入法和介质损耗法的低频介损在线监测方法,并分别通过仿真和实验对其原理和效果进行了研究。仿真部分包括热老化和水树老化2种老化方式电缆绝缘的监测,以及考虑噪声、低频频率波动和谐波对仿真结果的影响。实验部分包括分别制作热老化和水树老化电缆样本,设计实验电路对仿真结果进行验证。最后通过样本微观测试,对实验原理进行机理分析。仿真和实验结果表明,对于不同类型的老化电缆,以及绝缘的不同故障,都可以通过注入低频信号响应的低频介损判断电缆老化程度。In order to improve reliability of power system operation, it is an inevitable trend to perform online monitoring of cable insulation instead of traditional periodic maintenance to prevent power failure. All existing online monitoring methods have some limitations. Therefore, on the basis of existing studies, this paper proposes an online monitoring method of low-frequency dielectric loss combining signal injection method and dielectric loss method, and studies its principle and effect through simulation and experiment respectively. The simulation part includes monitoring of thermal aging, water-tree aging, and the influence of noise, low frequency fluctuation and harmonics on simulation results. The experiment part includes making thermal aging and water tree aging cable samples respectively, and designing experimental circuit to verify the simulation results. Finally, through sample microscopic test, the experiment principle is analyzed. Simulation and experiment results show that for different types of cable aging and insulation faults, the aging degree of cables can be judged by the low-frequency dielectric loss in response to the injected low-frequency signal.

关 键 词：电力电缆 绝缘在线监测 信号注入法 介质损耗因数 傅里叶算法 

分 类 号：TM721[电气工程—电力系统及自动化]