误操作引起3/2主接线开关跳闸的事故分析

Analysis of the tripping of the circuit breaker by error operation in the transmission line with breaker-and-a-half configuration

3/2主接线方式二次回路接线复杂,存在'和回路',容易引起误操作事故。介绍了一起误封电流互感器二次回路引起3/2主接线开关跳闸的事故。阐述了事故发生时的误操作过程,计算分析了误操作产生的零序电流,得出零序电流大于零序保护Ⅳ段定值的结论,并提出了先划开连片,再封CT的防范措施。

Transmission line with breaker-and-a-half configuration is complex. It includes ＂adding circuit＂, and some error operations always occur. The accident of the circuit breaker＇s tripping is introduced by the error operation in the transmission line with breaker-and-a-half configuration. The process of the error operation is introduced. The residual current by the error operation is computed. The reason of the tripping is analyzed. And the technical measure that the linker is disconnected and then the CT is connected is proposed.