为准确辨识输电线路雷击故障,分析了雷电绕击和反击的发生机理,并基于ATP-EMTP建立了110 kV输电线路杆塔多波阻抗模型及雷击仿真模型进行仿真。结果表明:雷击杆塔塔顶或绕击导线时,绝缘子串两端电位差方向不同;雷击闪络时,被击杆塔闪络相绝缘子串电位差降为0,雷击暂态过程结束后,邻近杆塔对应相绝缘子串电位差近似为0;反击闪络时,邻近杆塔绝缘子串两端电位差方向发生改变;杆塔入地电流方向可表征雷电流极性。基于上述特征,提出通过输电线路绝缘子串电位差和杆塔入地电流构建特征量,以2者的方向及其有效值作为识别判据,对雷击故障及未故障条件下的雷击类型进行辨识。
In order to identify lightning stroke faults on power transmission lines accurately, after discussing the me- chanism of back striking and shielding failure, we simulated and studied an 110 kV transmission line with multi-wave impedance tower model and a lightning simulation model established in ATP-EMTP. The results indicate that the direction of insulator voltage differs between shielding failure and back striking. When there is insulator flashover, the voltage of insulator decreases to zero, and after the transient process of lightning strike ends, the voltage of insulator on nearby tow- ers decreases to zero as well. When there is back fiashover, the direction of insulator voltage on nearby tower alters. Meanwhile, the tower current can characterize the polarity of lightning current. Based on these features, insulator voltage and tower current are introduced as the characteristic indexes, and their direction and effective values are used as the rec- ognition parameters for lightning stroke identification.