摘要
为考虑雷击架空输电线路后,雷电流在避雷线、杆塔、接地网和土壤中的动态散流过程,建立了输电线路-杆塔-接地网一体化雷电全波电磁暂态模型,计算冲击接地电阻和反击过电压。基于全波电磁暂态模型,从冲击接地的概念出发,将土壤电阻率、雷电流波前时间和幅值对输电线路的影响直接反映在雷电过电压上,对雷电过电压与冲击接地电阻计算公式进行拟合。研究表明:波前时间减小和土壤电阻率增大均会使冲击接地电阻值与雷电过电压增大。不考虑火花效应时的冲击接地电阻值与雷电流幅值无关,雷电过电压随雷电流呈正比例增大。在进行接地网设计时,应考虑能使雷电过电压值下降的接地网射线的有效长度。
In order to consider the dynamic dispersion process of lightning current in lightning protection line,tower,grounding grid and soil after lightning strike transmission line,the full-wave electromagnetic transient model of transmission line-pole-grounding grid is established to calculate the impact grounding resistance and counter overvoltage.Based on the full-wave electromagnetic transient model,from the concept of impact grounding,the influence of soil resistivity,lightning current wavefront time and amplitude on the transmission line is directly reflected on the lightning overvoltage,and the lightning overvoltage and the grounding resistance are calculated.The formula is fitted.Studies have shown that both the reduction of the wavefront time and the increase of the soil resistivity increase the impact grounding resistance value and the lightning overvoltage.The impact grounding resistance value regardless of the spark effect is independent of the lightning current amplitude,and the lightning overvoltage increases proportionally with the lightning current.When designing the grounding grid,consider the effective length of the grounding grid ray that can reduce the lightning overvoltage value.
作者
甘艳
顾德文
张昌
姚勇
黄瑞莹
GAN Yan;GU Dewen;ZHANG Chang;YAO Yong;HUANG Ruiying(Central China Branch of State Grid Corporation of China,Wuhan 430077,China;School of Electrical Engineering,Wuhan University,Wuhan 430072,China)
出处
《中国电力》
CSCD
北大核心
2018年第9期118-125,共8页
Electric Power
基金
国家电网公司华中分部科学技术项目(雷电冲击下线路-杆塔-接地极一体化全波建模机理及电磁暂态特性研究模型
HZ16-01)~~
关键词
500KV输电线路
雷电过电压
一体化模型
冲击接地电阻
防雷
500 kV transmission line
lightning overvoltage
integrated model
impact grounding resistance
lightning protection
