一起断路器控制回路直流接地的故障分析

Analysis of a DC Grounding Fault in the Control Circuit of Circuit Breaker

某500kV变电站220kV官徽4D81断路器SF6表计进水、凝露而引起二次回路直流操作电源绝缘故障、控制、信号回路异常,直接影响变电站的监视、控制、测量以及保护功能。运维人员通过现象分析,查找故障点,进行电气隔离。通过深入分析该原理,解析了故障的原因,最后从变电运维的角度提出此类故障处理策略。

In a 500kV substation,the water penetration and condensation of the SF6 meter installed at the 220kV Guanhui 4D81 circuit breaker caused the insulation failure of DC operating power supply,control and signal circuit abnormality of the secondary circuit,which directly affected the monitoring,control,measurement and protection functions of the substation.Based on the fault analysis,the operation and maintenance personnel found out the location and conducted the electrical isolation.An in-depth analysis was then made about the cause in terms of principle and strategies for handling this kind of fault was put forward from the perspective of substation operation and maintenance.