基于双回反向序网的同杆4回线单端故障测距算法

A New Fault Location Algorithm with One End-Data for Four-Circuit Transmission Line on the Same Tower Based on Double Opposite Sequence Network

提出了一种利用单端工频量的同杆4回线故障测距算法.采用同杆4回线双回同反序解耦方法计算得到考虑分布参数特性的故障线路沿线电压;采用同杆4回线双回反序网络计算得到考虑分布参数特性的故障电流分支系数,进而计算出故障线路沿线电流.由于故障支路可假设为纯阻性,因此利用故障处电压电流相量之比的虚部为0的特性进行故障位置搜索,最终实现同杆4回线中1回线内及2回线间跨线故障时的故障定位.本方法计算简单,不存在伪根问题,且不受系统阻抗、线路分布电容及过渡电阻的影响.仿真表明在同杆4回线各种故障类型下算法均具有很高的测距精度.

A new fault location algorithm for four-circuit transmission line on the same tower was proposed using power frequency quantities on one end. Considering distributed parameters of EHV four-circuit transmission line on the same tower, voltages along faulty lines were calculated based on double equidirectional and opposite sequences decoupling algorithm; branch coefficients of fault currents and currents along faulty lines were calculated based on double opposite sequence network. Because faulty branches are resistive no matter what the fault type is, the image of the phasor rate of voltage and current at fault point is 0. Based on this characteristic, fault location can be identified by searching for fault in single circuit or cross double circuits. Not affected by impedance of system at both ends, distributed capacitance and fault resistance, the algorithm can calculate at fast speed without false roots during the searching process. Simulation results indicate that it is of high precision.