基于长间隙放电研究雷电屏蔽问题的进展

长间隙放电是研究地面物体雷电屏蔽问题的最有效手段之一。首先介绍了国内外在雷电击距、直击雷防护措施的屏蔽性能试验和雷电迎面先导过程研究3个方面所取得的进展,并结合最新开展的长达6 m间隙尺度的放电试验观测,对现阶段上述3个方面研究所存在的问题进行了分析。认为基于雷电击距建立的电气几何模型(electric geometry model,EGM)仅适用于小尺度目标物的雷电屏蔽性能分析,现有的雷电屏蔽模拟试验方法仅能近似模拟不存在雷电迎面先导时的雷击过程,无法完全证明以提前流注发射模型装置为代表的非传统防雷装置具有比传统措施更优越的屏蔽性能。大尺度目标物的雷电屏蔽问题应聚焦于雷电迎面先导过程的研究,建立并完善雷电迎面先导过程的模拟试验方法和物理仿真模型。

Review of the Lightning Shielding Against Direct Lightning Strokes Based on Laboratory Long Air Gap Discharges

It is one of the most effective ways to use laboratory long air gap discharges for investigating the fundamental process involved in the lightning attachment.The research development on the lightning striking distance,the lightning simulation test and the positive upward connecting leader process by using laboratory long sparks were reviewed in this paper.According to the discharge observation results with the gap length up to 6m carried out in this paper,it is acceptable by using electric geometric model(EGM) to estimate the lightning shielding performance of small scale grounded objects,the existing lightning shielding simulation test does not take into account of the influence of upward connecting leaders,and the early streamer emission(ESE) device does not have the specified performance as it claimed.The lightning shielding performance investigation of large scale objects should focus on the inception and propagation of the positive upward leader,which aims to develop the simulation test methods of positive upward leader by using long sparks and to modify the physical simulation models.