基于双回线环流的时域法故障定位

该文提出了一种利用双端电流量实现双回线故障定位的时域测距算法。该算法利用双回线环流网与两侧系统无关且两端电压为零的特点，只用线路两端的电流量，就可计算出环流网的沿线电压分布，并根据从两端计算得到的电压分布差值在故障点处最小的原理实现测距。由于避免了使用电压量，故该测距原理不受电容式电压互感器(CVT)不能传变高频电压暂态信号的限制，该算法能够利用故障全过程的任何一段数据实现测距，且该算法所需数据窗短，只要略大于被测线路传输时问的2倍即可。该算法采用分布参数线模，克服了忽略线路电容带来的误差，适用于高压长距离输电线。仿真结果表明：测距误差将小于0．15km，且测距精度不受故障类型和过渡电阻的影响。

A NOVEL TIME-DOMAIN ALGORITHM FOR LOCATING FAULTS ON PARALLEL TRANSMISSION LINES BY CIRCULATING CIRCUIT

In fault states, parallel transmission lines can be uncoupled into Common Component Net and Differential Component Net. According to the fact that Differential Component Net is just constituted by parallel transmission lines part and its terminal-voltage is zero, voltage distribution along Differential Component Net can be calculated by terminal- current only. A new fault location algorithm is obtained by the principle that the least difference of voltage distribution computed by each terminal-current is exactly at the fault point. Because no voltage is involved in the proposed algorithm, there is no influence from CVT for which cannot transfer high frequency transient signal. From transient state to steady state, any segment of fault current can be used to locate faults by the algorithm. The algorithm needs an extreme short data window which is just a little longer than double propagation time of the parallel transmission lines. Using distributed parameter line model, the proposed algorithm is applicable for long distance lines since shunt capacitance is taken into account. Simulations show that, the locating error is less than 0.15km, and the fault types and fault resistances have no influence on locating precision.