一种适用于电流差动保护的T型高压输电线路故障测距算法

针对在T型线路的T节点附近发生短路,特别是高阻短路时,常用的T型线路故障测距方法会无法正确判断故障支路而存在一个测距死区的问题,提出了一种利用过渡阻抗的纯电阻性质进行故障测距的方法,并利用反证方法判断在T节点附近发生故障的支路。PSCAD仿真结果表明,该方法原理正确,无测距死区,测距精度不受故障类型、故障距离和过渡阻抗的影响,精度较高。

A Fault Location Method Applying to Current Differential Protection of T-type HV Transmission Lines

Aiming at the problem that traditional T-type line fault location method is not able to determine the correct fault section and leading to a dead zone, especially when the transition resistance is high, this paper proposes a new fault location method using pure resistance character of transition impedance and using proof by contradiction to determine the fault section when fault occurs near the T node. The PSCAD simulation results indicate that the theory of the method is correct and without dead zone; the location precision is high and not influenced by the fault type, fault distance and transition impedance.