一起线路与主变保护定值配合失当的事故分析

介绍了宁夏电网红寺堡变一条110 kV出线因鸟害造成的单相接地故障，从而导致该线路末端变电所主变零序过压保护误动作。通过结合实际保护定值对该故障进行了详细的分析，发现是由于电网中实际保护定值的配合失当，保护选择性和灵敏性不足引起的。在事故原因分析清楚后，通过对线路防鸟害、主变保护和线路保护定值校核整定方面提出了改进方案及对策。

Analysis on the accident of mismatch between line and transformer protection setting

This paper introduces a single-phase grounding breakdown caused by a bird damage that occurs in the 110 kV line in Hongsipu substation of Ningxia Power Grid,which led to the wrong action of the line end main transformer zero-sequence overvoltage protection.Based upon the practical protection setting value situation,and by analyzing the accident in detail,we find that the weak selectivity and sensitivity of practical protection and the improper coordination of relay settings are the main reasons.After the re...