电压切换插件烧毁问题的分析及解决方案

Analysis and solution of voltage switch plug-burning problem

介绍了一起110kV变电站电压切换插件烧毁故障,通过对该故障问题的查找和分析,找到了引起插件烧毁故障的原因:由于电缆电容及操作时的暂态过电压引起I母和II母产生压差,在I母和II母的电压切换回路中产生较大的短路电流;II段母线上还有其它很大负载回路及切换过程耦合串入的冲击负载电流,造成大电流通过了切换插件的触点。并提出更换刀闸辅助接点为真空型、用双触点启动电压切换回路、采用正确的母线倒闸顺序等有效的防范措施,从而保障了电力系统的安全稳定运行。

This paper introduces the 110kV substation voltage switch with plug-burning failure. Through the search and analysis, it finds the reasons of plug-ins burning failure. Because cable capacitance and the operation of the transient over-voltage cause Ⅰ bus and bus Ⅱ generate pressure, in the bus Ⅰand the bus Ⅱ voltage switching generates a greater short-circuit current; in Ⅱ segment there are other significant loads on the bus loop and the switching process coupled string into the impact of load current, which result in the adoption of high-current switching plug-in contacts. And it proposes that replacing knife auxiliary contacts for vacuum-type, with pairs of contact start-voltage switch circuit, and using the correct sequence of bus-switch and other effective preventive measures, thereby safeguarding the security and stability of power system operation.