出线近端接地故障发电厂设备故障特征分析

Analysis on Fault Characteristics of Power Plant Equipment With Outgoing Line Near-end Grounding Fault

通过某发电厂220 kV线路接地故障时的录波数据,对发电厂内各机组的故障特征进行分析,利用录波数据校核了继电保护整定计算书中的接地短路电流,计算并分析各机组故障电流的特征,发现了两台发电机定子接地保护中性点零序电压变比不一致的问题,分析了系统接地故障对厂用400 V设备的影响等。

Based on the recorded wave data of a 220 kV line grounding fault in a power plant,the fault characteristics of equipment in each of its units are analyzed.The grounding short circuit current in the relay protection setting calculation sheet is checked by using the recorded wave data.The characteristics of fault current for each unit are calculated and analyzed.The problem is found out that the neutral point zero-sequence voltage transformation ratio of the stator grounding protection of two generators is inconsistent,and analyses are conducted on the influence of a system grounding fault on 400 V plant equipment,etc.