变电站高压母线电压互感器故障调度处理方法的探讨

Discussion on Countermeasures against Faults of HV Bus Voltage Transformer in a Substation

结合某大型电网近年来几起母线电压互感器(voltage transformers,VT)事故处理的实例,从母线VT二次回路的结构与原理入手,对变电站高压母线VT故障的调度处理方法进行分析和探讨,认为在双母线分列运行方式下,2条母线VT的二次侧不能并列运行。同时提出有关保护配置和调度事故处理原则的改进建议,即:母线VT的二次空气开关跳闸时,若变电站现场规程允许,可以立即试合一、二次空气开关;故障点未有效隔离时,严禁进行常规的母线隔离开关"先合后分"的倒母线操作;完善继电保护装置的功能等。

In combination with examples of disposing voltage transformer （VT） accidents in a large power grid in recent years, the paper starts with structure and principle of secondary circuit of bus voltage transformer and analyzes and discusses on countermeasures against faults of HV bus voltage transformer in a substation. It is believed that in the separate operation of double bus, paralleled operation of secondary side of VT is prohibited. Furthermore, principles for accident proposal andimprovements on protection configuration, namely, on the condition that there is tripping of secondary air break switch of bus voltage transformer, the primary and secondary air break switch should be immediately switched on if it is allowed by field regulations. If the fault point is not effectively isolated, routine ＂switching on and then off＂ bus switching of bus is strictly prohibited; improvement of functions of relaying protection devices etc.