一起线路故障引发站内设备故障的多重电网故障分析  

A Detailed Analysis on Complex Power Grid Accident Caused by A Fault of 35 kV Line in Substation

作　　者：苟小刚 段然 崔明德 Gou Xiaogang;Duan Ran;Cui Mingde(Tianfu New District Electric Power Supply Company,State Grid Sichuan Electric Power Company,Chengdu 610021,Sichuan,China)

机构地区：[1]国网四川省电力公司天府新区供电公司

出　　处：《四川电力技术》2020年第1期59-62,共4页Sichuan Electric Power Technology

摘　　要：针对某110 kV变电站因35 kV线路发生单相接地故障导致站内主变压器总路断路器CT绝缘击穿,发生异名相两点接地短路的复杂电网事故进行了详细分析。该事故无法通过故障点判断是否属于主变压器差动保护区内故障,通过差流计算的方法证明了CT故障点在主变压器差动保护区区外,差动保护因CT受损波形畸变而动作。分析过程显示了故障细节对事故分析的重要性。Aiming at a complex power grid accident that CT had insulation breakdown in the substation caused by a single-phase grounding fault of a 35 kV line,which finally led to two points grounding short circuit occurred in different phases,a detailed analysis is carried out.Through the differential current calculation method,it is proved that the CT fault point moves outside the zone of main transformer differential protection,and the differential protection operates because of the distortion of CT damaged waveform.The analysis process shows the importance of fault details in accident analysis.

关 键 词：多重故障 故障分析 主变压器差动保护 区外故障 

分 类 号：TM774[电气工程—电力系统及自动化]