输电线路绕击耐雷性能对比研究

Comparative Study on Lightning Shielding Failure Proof Performance of Transmission Lines

指出雷电绕击引起的输电线路跳闸事故随电压等级的升高所占的比例越来越大。针对220kV、500 kV电压等级典型线路,分别利用规程法、优化法和电气几何模型法分析绕击耐雷性能,并对其结果进行分析比较。结果表明,优化法与规程法相比,电压等级越高,两者所得绕击跳闸率的差别越大;地面倾角是影响线路绕击跳闸率的重要因素之一,将地形简单地分为平原和山区不切合实际;对平原地区线路来说,用三种方法所得绕击跳闸率差别不大,可以用规程法和优化法对平原地区线路绕击耐雷性能进行简单估算;电气几何模型则更好地解释了山区线路绕击跳闸率异常高的现象。

With the increase of voltage level of transmission lines,the proportion of outages because of shielding failure increases. The shielding performance of 220 kV and 500 kV typical transmission lines are analysed by using standard method,optimization method and electric-geometry model,and the results are calculated and compared. The results show that the higher the voltage level is,the larger the difference of lighting trip-out rates is.The ground angle is one of the important factors that affect lighting trip-out rates,thus,it is not realistic to simply divide the terrain type into plains and the mountains. There is not much difference of lighting trip-out rates by using the three methods in the plain region,and the standard method and optimization method can be used to simply estimate the shielding performance at plain region while electric-geometry model can better explain the phenomenon of abnormally high lighting trip-out rates in mountain region.