220 kV线路断相导致零序过流保护动作的分析

Analysis of Zero-Sequence Overcurrent Protection Action Caused by 220 kV Line Phase-Break

本文分析了某发电有限公司220 kV线路零序过流Ⅲ段保护动作事件,根据故障录波数据排除了线路发生单相接地的可能,最终查明故障原因是隔离开关C相合闸不到位产生零序电流造成保护动作;分析总结了输电线路断相时的电气量特征,为快速定位故障性质提供了支撑;为避免再次发生隔离开关合闸不到位的问题,结合实际制定了严格执行定期检修、强化日常巡视检查和严把检修质量验收等相关防范措施。

This paper analyzes the zero-sequence overcurrent sectionⅢprotection action event of a 220 kV line of a certain power generation limited company,and identify the cause of the fault as the zero sequence current generated by the inadequate closing of one phase of the isolation switch,which caused the protection action.The electrical characteristics of the open-phase transmission line are analyzed and summarized,which can provide support for the fast determination of the fault nature.After analyzing and identifying the causes,measures will be taken to eliminate the faults,and relevant preventive measures such as strict implementation of regular maintenance,strengthening of daily inspections,and strict acceptance of maintenance quality will be formulated based on the actual situation.