输电线路两相短路故障的自适应分相重合闸方法

针对不带并联电抗器的超高压输电线路上发生的两相短路故障,提出一种自适应分相重合闸方法.搭建两相短路故障分析电路模型,推导出瞬时性故障下不同阶段选跳相端电压的时域表达式,分析选跳相端电压特性.研究发现,瞬时性故障二次电弧熄弧时,选跳相断路器两端电压的相角差由-120°突变到180°,且熄弧后恢复电压中出现明显的衰减直流分量.利用选跳相端电压的上述特征,提出了二次电弧熄灭时刻捕捉判据,实现了超高压输电线路上的自适应分相重合闸,并通过仿真验证了分析结果的正确性及所提方法的有效性.

An Approach to Adaptive Sequential Reclosure of Two Phase Short Circuit Fault in Transmission Lines

For the phase-to-phase short circuit fault occurred in transmission lines without shunt reactor, a method of adaptive sequential reclosure is proposed in this paper. A circuit model is built for analyzing the phase-to-phase short circuit fault, and the time domain expression of terminal voltage is deduced for the open-phase at different stages of transient fault. The recovery voltage characters of terminal voltage at open-phase is analyzed in detail. The theoretical analysis shows that the phase angle difference of terminal voltage at open-phase changes suddenly from -120° to 180° in the moment of arc extinction, and the decaying DC component appears obviously in the recovery voltage after the arc extinction. According to the above characteristics of terminal voltage at open-phase, a criterion was proposed to detect the arc extinction time and realize the adaptive sequential reclosure of transmission line. The simulations verified the correctness of the analysis result and the validity of the proposed method.