110kV线路接地故障与终端站保护配合案例分析

Analysis of Coordination of 110kV Line Grounding Fault with Terminal Substation Protection

针对110kV中性点直接接地系统中,主网终端且带地区电源的变电站在始端送电线路发生单相接地故障时,线路接地保护与终端变电站内相关保护的配合、整定问题,以华北电网发生的一起110kV线路单相接地故障为例,阐述了线路接地保护及终端带地区电源变电站主变压器零序电压保护的动作过程,分析了导致零序电压保护动作与变电站全站停电的原因、110kV主变零序电压保护的配置和110kV线路接地保护、地区电源联络线保护、重合闸与备用电源自投装置等配合问题,并对保护配置和整定提出了改进建议。

Aiming at the coordination and setting problem of terminal substation and line ground protection in 110 kV grounded neutral systems for single-phase earth fault occurring in the starting of power transmission lines of the main grid terminal substation with area power supply, taking 110 kV single-phase earth fault in North China power grid for an ex- ample, the action process of line grounding protection and main transformer zero-sequence voltage protection of terminal substation with area power supply is presented. And it analyzes the causes of zero-sequence voltage protection action and substation interruption of power supply, zero-sequence voltage protection configuration of 110 kV main transformer. Then, the matching problem of 110 kV line grounding protection, regional power supply tie lines protection, reclosing and backup power source automatic switch device is discussed. Finally, some suggestions are put forward for improving the protection configuration and setting.