基于Monte Carlo和EGM的同塔双回线路绕击跳闸率的计算

Calculation of Shielding Failure Trip-out Rate for Double Circuit Transmission Lines Based on Monte Carlo Method and EGM

为准确评价输电线路的耐雷性能,采用蒙特卡罗法对雷电绕击线路的随机过程进行统计计算。针对同塔双回线路的实际杆塔结构,改进了电气几何模型(EGM)作为绕击判据,考虑输电线之间的相互屏蔽作用以及雷电先导入射角,通过先导位置落入绕击区间进行绕击的判定。选取220 kV同塔双回线路的实际杆塔进行绕击跳闸率的计算,与已有算法的计算结果进行对比分析,验证了改进算法的合理性,并分析了先导入射角,避雷线横担长度,地面倾角对绕击跳闸率的影响。

For accurate evaluation on lightning withstand performance of transmission line, the stochastic process of lightning stroke is studied by using the Monte Carlo method. Considering the mutual shielding effects between the transmission lines and incidence angle of lightning leader, an improved electro-geometry model （EGM） is used to as criteria, which is through lightning leader failing into the Shielding interval to judge whether the transmission lines with double-circuits on the same tower are shielded. The shielding failure trip-out rate of 220 kV double circuit transmission lines is calculated, which is compared with existing algorithm. The analysis result verifies the reasonability of the improved EGM. The influence of incidence angle of lightning leader, length of ground wire cross arm and ground obliquity of the transmission lines is also analyzed.