装设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(metal oxide varistor,MOV)的非线性,使得一般线路的故障测距方法不能直接用于串补线路的故障测距。为此,在贝瑞隆(Bergeron)线路模型下推导了利用本端电压和对端电流计算本端电流的公式,并将推导公式运用于故障测距,提出一种串补线路故障测距算法,该算法利用双端电压电流进行测距,采用分布参数时域模型,理论上不依赖串补装置的模型,不受MOV非线性的影响。利用PSCAD和Matlab进行仿真,结果表明,该算法测距精度高,且不受故障类型、故障位置和过渡电阻的影响。
The conventional fault location algorithm cannot be directly applied to series compensated transmission lines because of the nonlinear V-A characteristic of metal oxide varistor (MOV) installed with the series capacitor (SC) in parallel. Therefore, based on the Bergeron line model, we deduced the current formula at the one end, using the voltage at the same end and the current at the other end. Applying the formula to the fault location, we presented a fault location algorithm for the series compensated transmission lines. In the proposed algorithm, two-end synchronous voltage and current data were used and the distributed parameter line model in the time domain was applied. The proposed algorithm does not use the model of series compensated device and is not affected by the nonlinear V-A characteristic of MOV in theory. PSCAD and Matlab were used for simulation. The simulation results show that the proposed algorithm has high accuracy, and is not affected by fault types, fault positions and fault resistances.