输电线路杆塔塔头引雷能力模拟试验研究

为了研究架空输电线路杆塔塔头的引雷效果,笔者建立了按1﹕25比例缩小的平原500 kV典型交流输电线路模型,采用标准操作冲击电压进行了大量的放电试验。通过试验数据分析,笔者得出了杆塔头部至输电线路档距中央方向的绕击概率的变化情况。结合现场运行经验和理论分析可知:杆塔头部的引雷能力明显,但其保护范围有限;在距离杆塔不远区域,输电线路的绕击概率最高。该试验不仅可以为雷电屏蔽模拟试验中电极放置位置提供参考依据,也指出了输电线路中需要加强防雷措施的易遭受绕击区域,对线路安全运行水平的进一步提高具有指导意义。

Study on Simulation Test for Triggered Lightning Ability of Transmission Line Tower Head

To study on the ability to triggered lightning of a overhead transmission line tower head,a typical 500 kV AC transmission line model with a ratio of 1:25 is established.Numerous discharging experiments are conducted with standard switching voltage impulse.With analysis on experimental data,variation of transmission lines shielding failure probability from the tower head to the middle line span is achieved in this paper.The combination of theoretical analysis and on-site operation experiences shows: Tower head’s triggered lightning ability is obvious,but it is limited in protection scope.The combination of operating experience and theory analysis shows that the tower head has obvious triggered lightning ability while its protective range is limited,and transmission line near the tower is of the largest shielding failure probability.The test described in this paper can provide reference to where electrode should be set on during shielding failure simulation tests,but also can indicate a transmission line range that can be easily suffered from shielding failure and needs more protective measures.This can be a guidance to improve more on the safety of transmission line operation.