变电站二次回路电缆接地线电流在线监测方法  

Online Monitoring Method for Ground Wire Current of Secondary Loop Cable in Substation

作　　者：陈昊 王玮 陈维佳 夏冰 陈旖旎 CHEN Hao;WANG Wei;CHEN Weijia;XIA Bing;CHEN Yini(Nanjing Power Supply Branch,State Grid Jiangsu Electric Power Co.,Ltd.,Nanjing Jiangsu 210019,China)

机构地区：[1]国网江苏省电力有限公司南京供电分公司,江苏南京210019

出　　处：《湖北电力》2023年第6期46-52,共7页Hubei Electric Power

摘　　要：针对变电站二次回路电缆接地线过热影响电缆绝缘寿命、引起电气火灾等问题,提出了一种变电站二次回路电缆接地线电流在线监测与预警方法及系统,通过引入屏蔽层接地线过流判据、铠装层接地线过流判据、局部环路过流判据、考虑对时修正的屏蔽层接地线差流判据和铠装层接地线差流判据,对3类典型的接地线发热情况进行研判,显著提升了二次回路电缆状态监测效率和故障研判精度,为变电站智能运维提供了技术支撑。江苏省某500kV变电站的工程实践验证了该方法及系统的有效性和可行性。The overheating of the grounding wire of the secondary circuit cable in substation will affect the insulation life of the cable and cause electrical fire.In order to solve this problem,the paper proposes a method and system of online monitoring and early warning of the ground wire current of the secondary loop cable in substations.Through the introduction of shielding layer ground wire overcurrent criterion,armor layer ground wire overcurrent criterion,local loop overcurrent criterion,shielding layer ground wire differential current criterion considering timing correction,and armor layer ground wire differential current criterion,three typical grounding wire heating conditions are studied and judged,which significantly improves the monitoring efficiency and fault detection accuracy of the secondary loop cable condition,thus providing technical support for intelligent operation and maintenance of substations.The engineering practice of a 500 kV substation in Jiangsu province verifies the effectiveness and feasibility of the proposed method and the system.

关 键 词：二次回路电缆 接地线电流 复合判据 状态监测与预警 智能运检 

分 类 号：TM63[电气工程—电力系统及自动化]