基于分布参数模型的串联补偿双回线单线故障定位算法

摘要

对于装设串联补偿(串补)装置的输电线路,由于与串联电容并联的保护元件金属氧化物可变电阻(MOV)的非线性特征,使得串补线路无法直接使用常规的输电线路故障测距方法.为此,提出了一种基于分布参数模型的串补双回线故障定位算法.按照故障点相对于串补的位置分为两个子算法,利用从本端、对端推算得到的故障点处电压相等的特点,消去串补装置近故障一侧的电压,结合故障点处过渡电阻的纯电阻性和故障序网边界条件,构造故障定位函数.该方法不依赖串补装置模型,不受MOV非线性的影响,无需预知串补装置相对于故障的位置,同时不存在伪根判别问题.EMTDC/PSCAD和MATLAB仿真结果计算验证了该方法的正确性.%The conventional fault location algorithm cannot be directly applied to the series compensated transmission lines because of the nonlinear characteristic of the metal oxide varistor (MOV) installed with the series capacitor (SC) in parallel.For this reason, this paper presents a fault location algorithm for the series-compensated double-circuit transmission lines based on the distributed parameter model.The algorithm is divided into two subroutines according to the fault position relative to the left or right side of the series compensator.For each subroutine, the voltages of the series compensated devices are eliminated according to the features that the sequence voltages calculated from local and opposite buses are equal at the fault point.Since the transition resistance is pure resistant at the fault point, the fault location equation can be created according to the boundary condition of the fault sequence current.The proposed algorithm does not use the equivalent model of series compensated device and is not affected by the nonlinear characteristic of MOV.In addition, there is no need to predict the location of the series compensation device relative to the fault point, nor is there any pseudo root elimination problem.The simulation and calculation results of EMTDC/PSCAD and MATLAB have verified the proposed algorithm.