一起500 kV线路PT二次回路N600混接缺陷整改及分析  

Modification and Analysis of N600 Mixing Connection Defects in PT Secondary Circuit of 500 kV Transmission Lines

作　　者：赵康宁 ZHAO Kangning(Suzhou Power Supply Company,Suzhou 215008)

机构地区：[1]国网江苏省电力有限公司苏州供电分公司,江苏苏州215008

出　　处：《电力安全技术》2025年第3期72-75,共4页Electric Safety Technology

摘　　要：对于运行中的变电站,若PT二次回路中性点N600虚接或失去接地,当系统发生故障时,中性点电位会因干扰电压而发生偏移,影响保护装置对电压的准确测量,从而引起保护不正确动作。现结合一起500 kV线路PT二次回路N600混接缺陷查找及整改情况,对中性点N600接地不良导致电压不平衡进行了理论分析,并提出了PT二次回路N600验收方法及日常运行维护建议。As for a running substation,if the PT secondary loop neutral point N600 is falsely connected or loses grounding,once the system fails,the neutral point potential would be offset due to the interference voltage,which would affect the accurate measurement of voltage by the protection device,thus causing an incorrect protection action.Combined with the search and modification of N600 hybrid connection defects in PT secondary loop of a 500 kV line,the voltage imbalance caused by poor grounding of neutral point N600 is theoretically analyzed,and the PT secondary loop N600 acceptance method as well as its routine operation and maintenance suggestions are put forward.

关 键 词：电压互感器 二次回路中性点 电压不平衡 接地 

分 类 号：TM726[电气工程—电力系统及自动化]