采用单档距走廊法分析高压输电线路的存在对地闪的影响

Analysis of Lightning Activities After the Erection of HV Transmission Lines Using Statistical Method of Single-span Corridor

针对现行高压输电线路防雷设计规程中采用传统区域落雷参数进行分析的不足,在进行输电线路差异化雷电防护工程中,分析输电线路的架设对走廊区域雷击落点分布的影响显得十分必要。为此,基于引雷空间理论及珠江三角洲地区已有的输电线路参数,建立了单档距走廊法统计模型,对山地、近水域及平原等不同地形环境下输电线路走廊区域的地闪定位数据进行了筛选,分析了输电线路架设前后雷电活动及地闪幅值概率分布规律。基于有限元-模拟电荷法,对雷云先导与大地均匀静电场在置入输电杆塔前后的电场进行了数值计算及模拟仿真;根据雷电发展路径与空间电场最强方向一致原理,分析了输电线路的架设对于地闪分布规律影响的物理过程。结果表明:采用单档距走廊法描述输电线路沿线走廊的地闪分布特征更有针对性;不同地形环境下,输电线路的架设对于雷击落点具有吸引效应,从而导致地闪在走廊区域的分布概率显著增大;同一电压等级输电线路走廊区域,山地环境下输电线路的架设致使地闪活动的增加较为明显,而平原环境与近水域区段相对较小。

Because of the inadequate analysis of traditional regional lightning parameters on the existing lightning protection design procedures of HV transmission lines,during the differentiation lightning protection project of transmission lines,it is necessary to analyze the impact of lightning point distribution after the erection of transmission lines.Based on the theory of attractive volume of lightning and combined with the parameters of exiting transmission lines of the Pearl River Delta region,the statistical method of single-span corridor was established.The lightning location data of corridor area of transmission line under different terrain environment,such as the mountains,and plain terrain,were selected.The distribution of lightning activity and amplitude probability of lightning current before and after the erection of HV transmission lines was analyzed.And based on the finite element-charge simulation method,numerical calculation and simulation of the electrostatic field of lightning leader and ground was established before and after the erection of HV transmission tower.According to the principles of the development path of lightning and the strongest electric field with the same direction,the physical process of impact of distribution of ground flash caused by the erection of transmission lines was analyzed.The results show that the statistical method of single-span corridor more focuses on describing the distribution of lightning.And in the same voltage transmission line,there exists a large impact of ground flash activity in different terrain environment on the erection of transmission lines and electrical tower,and the probability of lightning point in the corridor is increased significantly.Moreover,in the same voltage transmission line,there exists a large impact of ground flash activity in mountain environment on the erection of transmission lines and electrical tower,and small changes in distribution of plain terrain and the area near river.