特高压交流输电线路绕击耐雷性能仿真分析

Simulated Analysis of Lightning Shielding Failure Performance of UHVAC Transmission Lines

准确评估特高压(UHV)线路绕击耐雷性能,对线路设计及施工具有重要参考价值。为此,引入了基于先导发展法的,可精确反映任意剖分区域导、地线弧垂及与大地实际相对高度的特高压输电线路雷电绕击3维剖分模型。为进一步验证该模型的实际应用价值,分析了我国晋东南—荆门1 000kV特高压交流示范线路绕击耐雷性能,及绕击跳闸率随保护角、地面倾角的变化规律。分析结果表明:ZMP2型猫头塔最大绕击跳闸率为0.057 5次/(100km.a),ZBS2型酒杯塔最大绕击跳闸率为0.032 2次/(100km.a),两型杆塔的绕击跳闸率均满足设计要求,工程中可通过适当控制导、地线的弧垂来降低线路的绕击概率;山坡外侧导线更易遭受雷击,线路绕击跳闸率随线路保护角及地面倾角增大而大幅度上升;大电流绕击发生在距线路较远处。

Accurately assessing the shielding performance of ultra high voltage（UHV） transmission lines has a great reference value for design and construction of lines.We introduced a method for analyzing the shielding failure rate（SFR） of UHV transmission lines based on leader progression model（LPM） and three-dimensional dividing of shielding failure region,in which the actual arc sags and heights from local ground of transmission and grounding conductors in the areas were divided into any scale.To verify the method,the shielding failure trip rate（SFTR） of the 1 000 kV UHVAC demonstration line in China and its relation to shielding angel and slope gradient were calculated.Conclusions can be drawn as follows： the SFTR of the ZMP2 and ZBS2 towers in typical plain and mountainous terrain are 0.057 5 times/（100 km · a） and 0.032 2 times/（100 km · a）,respectively,which are acceptable for safe operation of UHV transmission lines in China;the SFTR can be lowered by adjusting sags of the conductors;the conductors at outside of the mountain slope is easier to be struck,and the SFTR increases with shielding angle and slope gradient;the shielding failure under large current occurs far away from the lines.