不同类型避雷针雷击接闪效能差异的实验评价方法

Experimental Evaluation Method for Lightning Attractive Efficiency Difference of Different Lightning Rods

探讨一种直观、易于理解且反映雷击放电机理的实验方法,以评价不同类型避雷针的雷击接闪效能差异,对雷电防护领域形成共识显得尤为重要。为此,论文首先分析了雷电环境下地面目标物上避雷针的雷击接闪过程,指出不同类型避雷针接闪效能的差异主要体现在对迎面放电过程的影响上;接着,提出了如下实验评价方法:采用针-板间隙的放电实验布置,对4 m及以上间隙施加1.2/50μs标准雷电波模拟迎面流注放电过程,对6 m及以上间隙施加250/2500μs标准操作波模拟迎面先导放电过程;然后,通过比较非传统避雷针与传统避雷针的放电起始时刻与平均发展速度2个指标,以评价不同类型针的接闪效能差异;最后,利用所提方法对典型提前放电(early streamer emission,ESE)非传统避雷针与传统避雷针开展了接闪效能差异的评价实验。实验结果表明:ESE针与传统避雷针的评价指标基本一致,不具备研发商所宣称的引雷增效作用。

There is an increasing demand for an intuitive and easy-to-understand experimental evaluation method for the lightning attractive efficiency difference of different lightning rods based on the lightning discharge mechanism;however,it is necessary to reach a consensus in the field of lightning protection.The lightning attachment process of rods on grounded objects in a lightning environment was analyzed in this study to illustrate that differences in lightning attractive efficiency are mainly attributable to the upward discharge process.An experimental evaluation method for lightning rod attractive efficiency was developed accordingly.A 1.2/50μs standard lightning impulse wave was applied to the rod electrode with a rod-plate gap of 4 m and above to simulate the upward streamer discharge process,then a 250/2500μs standard switching impulse wave was applied to a gap of 6 m to simulate the upward leader discharge process.The performance of a non-conventional lightning rod and a conventional lightning rod was compared in terms of inception time and average propagation speed.An experiment was carried out to evaluate the lightning attractive efficiency difference between the typical non-conventional lightning rod of ESE(Early Streamer Emission)and a conventional lightning rod.The results show that ESE rod performs similarly to conventional lightning rod,lacking the enhanced protective effects claimed by the manufacturers.