摘要
雷击是造成输电线路故障的主要原因之一,为研究平原和山区特高压输电线路遭受雷击的差异性,以1:12.5比例缩小的特高压SZ322型塔为研究对象,利用负极性80/2 500μs操作冲击电压.波,分别展开了平地和山区2种不同地形条件下的缩比线路雷击模拟放电试验,并结合空间静电场分布仿真计算对2种地形上放电路径分布的差异性进行定性分析。试验及仿真结果表明:平原和山区2种地形上放电路径选择性存在明显的差别,输电线路附近遭受雷击时,相对于平原上,斜山坡上输电线的电场强度更大,且下行先导头部的电场强度最大区域明显向输电线路侧偏移,因此山区的输电线更容易遭受雷击,大地的屏蔽效果差。当放电间隙尺寸增大时,结论依然成立,且2种地形上线路的绕击率差距增大,但两者的绕击率均下降,同时大地的屏蔽效果增强。研究结果对特高压输电线路雷电防护工作具有一定的参考意义。
Lightning stroke is one of the main reasons that cause faults in transmission lines. To study the effect of topography on the lightning performance of UHV transmission lines, with negative 80/2 500μs switching impulse voltage, large-sized model of the SZ322 tower with the ratio of 1：12.5 for 1 000kV UHV transmission lines was used to conduct the simulation tests in plain and mountain areas in this paper, besides, test results were qualitatively analyzed by simulation of space electric field. The test and simulation results show that the selectivity of discharge path in mountain area is obviously different from that in plain area. When lightning happens near the transmission lines, compared with the lines on flat ground, the electric field intensity of lines on hillside is stronger and the strongest part of electric field intensity around lightning leader is much closer to the transmission lines, thus, shielding failure rate of transmission lines in mountain area is higher and shielding effect of ground is poor. When discharge gap distance is increased, the conclusion remains valid and disparity of shielding failure rate of transmission lines in the two areas widens, but shielding failure rate of transmission lines in both areas decreases and shielding effect of ground strengthens. The obtained results may provide reference to lightning protection for UHV transmission lines.
出处
《电网技术》
EI
CSCD
北大核心
2015年第1期118-122,共5页
Power System Technology
基金
中国博士后科学基金项目(2014M560624)~~
关键词
特高压
雷击特性
模拟试验
地形
放电路径
静电场计算
UHV lightning performance simulation tests topography discharge path electrostatic field calculation
