两台主变零序保护误动分析

Analysis on maloperation of zero sequence protections for two main transformers

2 0 0 0年 7月 12日舟山电网定海电厂检查WXH 11x线路微机保护的开口三角电压极性工作中 ,由于主变零序保护元件触点误接 ,因试验需要 ,接线更改后造成定海电厂 4#、5 #主变零序保护误动作 ,引起定海电厂与舟山电网解列 ,分析原因 ,以期对类似工作有所借鉴。

On July 12, 2000, a routine maintenance on opened △ voltage polarity in WXH-11x microprocessor based transmission line protection was done in Dinghai Power Plant in Zhoushan Power Network and a wrong wiring of zero sequence protection element for main transformer was found. For testing, the wiring was corrected but caused the maloperation of the protections for #4 and #5 main transformers and therefore brought the Dinghai Power Plant into insulation from Zhoushan Power Network. The causes are analyzed and it will be helpful to the future work.