35kV系统双母线TV二次电压非正常并列事故原因分析及防范措施

Cause Analysis and Preventive Measures of TV Secondary Voltage Abnormal Concatenation in 35 kV Double-bus System

针对35 kV系统双母线电压互感器二次电压切换不成功造成插件烧毁的故障,结合电压切换原理,分析了事故原因是由于刀闸辅助接点不通,使双位置继电器不能可靠复归,造成两TV二次电压非正常并列,引发事故。提出应尽量避免双母线分列运行,加强对刀闸辅助接点的维护以及考虑采用单位置继电器等防范措施。

For the fault of plug-burning result from voltage transformer secondary voltage switch unsuccessful in 35 kV double-bus system, combining of the voltage switch principle, the paper analyzed the cause of the fault, which is disconnected switch auxiliary contacts connected failure, results in the two position relay can＇t return reliably and the two voltage transformers secondary voltage non-normal concatenation, and than leaded to the fault. In the paper, some preventive measures were proposed finally, preventing from the double-bus separated operation, improving maintain of the disconnected switch auxiliary contacts and considering of using the single position relay.