基于负序电流的同杆多回线路故障选线研究

Study on Line Selection for Multi-loop Line Fault at Same Tower Based on Negative-sequence Current

基于各类不对称故障时负序网络统一的拓扑结构,研究了负序电流的幅值与相角变化规律。研究结果表明,当多回线路发生单回线不对称故障时,故障线路与非故障线路的负序电流比相角趋于0°或180°,以此作为该类故障的识别依据,并在此基础上借助故障线路和非故障线路的幅值大小关系,进一步选出故障线路。由于回避了多回线中复杂的解耦计算,方便易行。大量的仿真实验验证了该方法的正确性和有效性。

The variation patterns of the amplitude and phase angle of negative current were studied based on the unified topological structure of negative sequence network at the time of various asymmetric faults.Study results showed that when asymmetric faults of single circuit occurred in the multi-loop line,the phase angle of negative sequence current ratio between the fault line and the normal line turned towards 0°or 180.This can serve as the basis for the recognition of this kind of fault on which the fault line was identified further by size relation between the amplitudes of the fault line and the normal line.The evasion of the complicated decoupled computation in the multi-loop made it convenient and easy to implement.The correctness and effectiveness of this method were verified by numerous simulation tests.