可控放电避雷针对引雷塔引雷能力的影响研究

The Effect of Triggering Lightning Tower with Controllable Lightning Rod on the Ability of Lightning Tower to Attract Lightning

为探究避雷针对引雷塔引雷能力的影响机理,设计了1∶12.5的缩比引雷塔模型,利用波形参数为-250/2500μs的负极性操作波对缩比模型塔开展接闪放电试验。模型塔接闪放电试验分为单塔间隙放电试验和双塔选择性放电试验两个部分,在单塔间隙放电试验中,通过试验观测平台对间隙放电的过程进行记录,并采用升降法获取不同工况条件下间隙50%的放电电压;在双塔选择性放电试验中,采用高速摄像系统对放电过程进行观测,同时对塔顶接有不同避雷针的两塔放电次数进行了统计。试验结果表明:在长度为1 m的空气间隙下,装有可控放电避雷针的模型塔较装有普通避雷针的模型塔更容易发生接闪,不同于普通避雷针的迎面流注的连接位置,可控放电避雷针上行先导的连接位置要更靠近高压电极的头部,且平均放电电压和平均击穿时间也要更小一些。分析认为,可控放电避雷针具有提前预放电的能力,较普通避雷针更容易产生上行先导,改变了模型塔顶部的空间电场分布,进而影响了模型塔的引雷能力。

In order to explore the impact mechanism of lightning protection on the triggering lightning tower’s lightning protection capability,a 1:12.5 scale model was designed,and a negative polarity operational waveform with a waveform parameter of-250/2500μs was used to conduct the lightning discharge test on the scaled model tower.The model tower flashover test is divided into single tower gap discharge test and two towers selective discharge test.In the single-column gap discharge test,the gap discharge process is recorded by the test observation platform,and the discharge voltage of 50%of the gap under different working conditions is obtained by the lifting method;in the double-tower selective discharge test,the high-speed camera system is adopted.The discharge process was observed,and the number of discharges of the two towers with different lightning rods at the top of the tower was counted.The effect of the type of lightning rod under different conditions on the lightning capacity of the tower was simulated,the discharge voltage of 50%of the gap under different working conditions is obtained by the up and down method,and the discharge process is observed.The test results show that under an air gap of 1 m in length,the model tower equipped with controllable discharge lightning rods is more likely to catch lightning than the model tower equipped with ordinary lightning rods,and the average discharge voltage and average breakdown time are also smaller.The analysis shows that the ability of the controlled discharge lightning arrester to advance pre-discharge is more likely to generate an up-lead than the common lightning arrester,thus changing the distribution of the space electric field at the top of the model tower,and thus changing the lightning-receiving ability of the model tower.The test results provide data support for triggering lightning tower’s lightning protection design.