带并补的超高压输电线路单相自适应重合闸新判据

A New Criterion for Single-phase Adaptive Reclosure of Shunt Reactor Compensated EHV Transmission Lines

带并联电抗器的超高压输电线路发生单相瞬时性故障时,二次电弧熄灭后断开相端电压及并联电抗器电流因含有自由振荡分量而呈现拍频特征,永久性故障时则基本为基波量。在分析故障相断开后的序网的基础上,给出了自由分量频率的正确计算方法,提出了利用正弦函数的正交性检测自由分量从而快速判断故障性质的拍频新判据,有效解决了拍频周期较长时利用现有判据判断故障性质所需时间较长的问题。该判据原理简单,判断速度快且具有较高灵敏度。仿真实验验证了所得结论。

When a temporary single-phase fault occurs on shunt reactor compensated EHV or UHV transmission lines, the voltage of the opened phase conductor and the current of the shunt reactor contain resonant component and power frequency component after the secondary arc is extinguished. While for a permanent single-phase fault, the above voltage and current only contain power frequency component. Based on the analysis of the circuit in which the faulted phase is opened, the method of calculating the resonant frequency is deduced. A new criterion based on the orthogonality of sine functions is proposed to detect the resonant component and determine the fault nature quickly. The proposed criterion can reduce the time to distinguish between permanent and temporary faults. The criterion is simple with high sensitivity. Simulation results show that the proposed conclusions are correct.