500kV交流线路故障跳闸的非典型动作过程探析

Analysis and Suggestions on an Atypical Action of 500 kV AC Line Trip

一条典型3/2接线方式的500 kV交流线路发生单相永久性接地故障,2套线路保护及2个开关保护动作情况均不一样。针对故障录波图和保护装置动作逻辑进行综合分析,发现5043开关本体三相不一致时间继电器计时不准确,导致了保护动作行为的不同,提出了对所有开关本体三相不一致时间继电器进行校验和更换的建议。

Permanent single-phase grounding fault occurred on a 500 kV AC line with typical 3/2 wiring way, and neither the two sets of line protection systems nor the two sets of switch protection systems act the same. For such situation, fault recorder and protection logic are analyzed comprehensively. It is found that inaccurate relay timing of three-phase inconsistence timing relay of 5043 switch body is the main reason. It is proposed to check and replace all the three-phase inconsistence time relay.