一起直流母线失电故障的分析与对策

Analysis and Countermeasures of a DC Bus Failure

介绍了一起220kV变电站蓄电池组内部断线异常。在主变低压出线发生故障,母线电压降低引起站用交流失电,直流充电机停止工作后,造成直流母线失电,引起部分保护拒动、部分保护误动故障。叙述了故障发生经过,介绍了故障处理过程,分析了保护拒动与误动的原因。直流系统是变电站可靠运行的保证,从直流系统的配置、充电模块的选择、电源切换的方法、蓄电池组的运行与维护等方面进行了分析,提出了提高直流系统供电可靠性的建议与对策。

This paper discusses an internal disconnection of battery group in a 220kV substation. During the abnormal a line fault in low voltage Side of the main transformer causes the 35 kV bus-bar voltage reduce, thereby the auxiliary power system failed, then the charger stop working. All of these lead to some of the breakers maloperation and some of the breakers miss trip. The paper discusses the process of the fault and analyses the reason of the breakers miss operation or refuse operation. DC system is the guarantee of reliable operation of the substation. This paper analyses the DC system from system configuration, charger modular selection, and battery group operation and maintenance, and put forward some suggestions and countermeasures to improve the reliability of DC system＇s operation.