同杆并架双回线阻抗选相方法研究

Research on Phase Selection Method Based on Impedance Measurement for Double-circuit Line

针对现有选相方法在同杆并架双回线跨线故障容易发生误选相的问题,提出了一种适用于同杆双回线的阻抗选相方法。新型选相方法主要利用了相间、单相阻抗大小及相位关系,为了实现在跨线故障、出口故障等情况下的准确选相,还补充了其它辅助判据以构成完整的选相方案。仿真计算表明,新的选相方法在同杆线路跨线故障、高阻接地、弱馈等故障情况下都有比较好的选相能力,适用于作为同杆并架线路保护故障选相元件。

In order to solve the misoperation problem of the traditional phase selector for the cross-country fault of doublecircuit line, a new phase selection method based on impedance measurement for double-circuit line is presented. The relationship between the magnitude and phase angle of the fault impedance are used in this new method. For the crosscountry fault and the close-in fault, other supplementary criteria are used. Its response to a number of fault conditions such as cross-country fault, high impedance ground fault or fault in weak infeed system are verified by the simulation tests. The results show that the new method is suitable for the fault phase selection element of the double-circuit line.