一起电缆金属屏蔽层接地线安装错误引起保护越级动作事故分析

Accident Analysis of the Overstep Protection Tripping Caused by the Wrong Installation of Cable Metal Shielding Layer Grounding Wire

为提高电缆敷设和安装工程管理的质量,提高电网运行稳定性与供电可靠性,结合生产实际情况,以某220 kV变电站的一起线路故障保护拒动,主变低压侧越级跳闸事故为例进行了分析,讨论了电缆屏蔽接地线安装方式对零序电流保护的影响,完善运维人员对电缆施工的管控措施,提高了供电可靠性。

In order to improve the quality of cable laying and installation engineering management,and enhance the stability of power grid operation and power supply reliability,a cause analysis is made for the tripping accident of the low voltage side of the main transformer caused by a line fault protection failure in a 220 kV substation.This research analyzes the influence of the installation mode of cable shielding grounding wire on zero-current protection,improves the control measures of operation and maintenance personnel on cable construction,and improves the reliability of power supply.