模拟线路地形下雷击放电路径差异性定性分析

Qualitative Analysis on Lightning Discharge Path Difference under Simulation Line Terrain

架空线路由于传输距离长、架设位置常位于孤立开放空间等原因导致其遭直接雷击或雷击线路走廊内概率较高,本研究旨在实现基于GPS测量地形数据建立实际地形横断面图,仿真计算特定地形下雷暴空间静电场及雷电先导在不同高度时刻雷击电磁场分布及变化特性,分析不同地形(山地、平原及建筑群区)影响雷电先导发展电磁环境影响线路附近空间电场变化趋势,得出雷暴静电场下、不同先导高度下、先导带点电荷不同位置分布以及不同地形条件下电场强度分布特性及畸变程度,继而对线路附近空间不同位置接闪放电路径概率进行差异性定性分析,最后利用仿真电场畸变及预判放电路径结果对线路雷击防护作具体考量。

Overhead line has high probability of the direct lightning strike or lightning strike at line corridors due to the long transmission distance,and its erect position is often located in isolated open space. It is tried to establish the actual terrain cross-sections based on GPS measurement terrain data,and simulating calculate the lightning electromagnetic field distribution and change characteristics of thunderstorm space electrostatic field and lightning leader under the specific topography at different heights moment,analyze the effect of different terrain（mountains, plains, and complex area） on lightning leader electromagnetic environment development as well as space electric field change trend near lines. The electric field intensity distribution features and distortion degree under thunderstorms electrostatic field with different leader height,different location distribution of leader charge and different terrain conditions are obtained,subsequently difference qualitative analysis on lightning discharge path probability for different location near the line is carried out,finally specific considerations on line lightning protection is carried out by using the result of electric field distortion simulation and anticipation discharge path.