220kV同塔四回输电线路绕击耐雷性能分析

Analysis on Lightning Withstand Performance of Shielding Failure for 220 kV Quadruple Circuit Transmission Lines

同塔四回输电线路杆塔高、引雷面积大,更易遭受雷击,220 kV线路绝缘水平相对较低,雷击线路导致跳闸的概率较大,开展220 kV同塔四回输电线路绕击耐雷性能研究具有重要意义。全面考虑导线间的相互屏蔽作用及工作电压的影响和雷电先导入射角的分散性,采用暴露弧投影距离建立了适合同塔多回输电线路绕击耐雷性能计算的电气几何模型(EGM),分析了不同击距公式对结果的影响,并与实际雷击跳闸数据对比,得到了适用于东莞地区绕击跳闸率计算的击距公式。基于此研究了地面倾角,杆塔结构等对同塔多回输电线路绕击耐雷性能的影响。

Due to the ultra-high tower and great area of triggered lightning, the quadruple circuit transmission lines can be more easily stricken by lightning. The insulation level of 220 kV transmission line is relatively lower which results in higher tripping probability of transmission lines. Therefore, it has significant meaning to carry out the research on lightning withstand performance of shielding failure for 220 kV quadruple circuit transmission lines. By fully considering the mutual shielding effect producing on one conductor caused by any other conductors as well as operating voltage influence and dispersion of lightning leader incident angle, an electric geometry model （EGM） is proposed which can be adopted to accurately calculate the lightning withstand performance of shielding failure for quadruple circuit transmission lines, using exposure arc projection distance. The effect on calculation results caused by adopting different strike distance formula is analyzed and compared with the actual lightning trip-out rate, thus the applicable strike distance formula which can be used to calculate shielding failure trip-out rate in Dongguan region is obtained. Based on what has established, the effect on lightning withstand performance of shielding failure for quadruple circuit transmission lines cased by ground elevation, tower structure and so on is studied.