500 kV紧凑型耐张杆塔绕击耐雷性能精细化分析方法

Elaborate Method for Analyzing Shielding Lightning Performance of 500 k V Tension Tower in Compact Transmission Line

为了解决500 k V紧凑型耐张杆塔塔头结构复杂,传统绕击跳闸率计算方式无法准确计算此类杆塔绕击跳闸率的问题,通过建立500 k V紧凑型耐张杆塔精细化模型,提出了基于全档距绕击耐雷性能分析方法的紧凑型耐张杆塔绕击跳闸率分析方法,并研究了此类型杆塔在拆除分支地线前后绕击跳闸率的变化。分析结果表明,拆除分支地线后,杆塔的绕击跳闸率提高约16.3%,针对这种情况考虑加装塔头侧针来改善线路防绕击性能。研究结果表明,安装塔头侧针可以显著降低杆塔绕击跳闸率,当3个跳线横担均加装塔头侧针时,可使杆塔的绕击跳闸率降低约59.25%。研究成果对指导我国500k V紧凑型耐张杆塔防雷改造提供了重要的参考依据。

The structure of head of 500 kV tension tower of compact transmission line is complex, and shielding failure trip-out rate of this kind of tower catmot be calculated precisely by traditional calculation method. By establishing an elaborate model of 500 kV tension tower of compact transmission line, we proposed an analysis method of lightning shielding failure trip-out rate of tension tower of compact transmission line on the basis of analysis method of whole span lightning shielding performance, and researched the shielding failure trip-out rate of this kind of tower before and after dismantling ground wire branch. The analysis results show that, after ground wire branch being demolished, the shielding failure trip-out rate of the tower will increase by about 16.3%. Therefore, tower lateral rod is proposed to improve light- ning shielding performance. The research results indicate that installing tower lateral rod can notably lower the lightning shielding failure trip-out rate of the tower. Moreover, when three tower lateral rods are respectively installed in three jumper cross arms, the shielding failure trip-out rate of the tower can be lowered by about 59.25%. The research results will provide valuable references for lightning protection renovation on 500 kV tension tower of compact transmission line in China.