500 kV线路互感导致系统零序电压和零序电流异常增大的分析和处理

Analysis and Treatment of Abnormal Increase of Zero Sequence Voltage and Zero Sequence Current Caused by Mutual Inductance of 500 kV Lines

文章介绍了一起500 kV线路事故,该线路因同杆4回线架设的制约,部分区域三相换位不充分,导致线路间的互感很大。在部分线路冷备用时,线路保护装置因零序电压大而报警的事故。根据报警信息的提醒,分析系统中可能出现的零序电压和零序电流,并进一步进行仿真模拟计算,得到系统零序电流的具体分配,定位主要受影响的设备,然后进行设备影响分析并采取对应措施进行处理。

This paper introduces an accident of 500 kV transmission line,which is restricted by the erection of 4-circuit lines on the same pole,and the three-phase transposition in some areas is not sufficient,resulting in great mutual inductance between lines.When some lines are cold standby,the line protection device gives an alarm because of the large zero sequence voltage.According to the warning information,the zero sequence voltage and zero sequence current which may appear in the system are analyzed,and the simulation calculation is carried out to get the concrete distribution of the zero sequence current in the system,and to locate the main affected equipment,then carry on the equipment influence analysis,and take countermeasures to deal with it.