基于源电荷模式的改进型地闪先导在有耗大地情况下电场分布特征

基于源电荷先导模式建立了适用于有耗大地情况下先导电场的计算模型,并利用人工引雷观测数据对模型进行了验证。运用新模型通过对有耗大地情况下地闪先导电场影响因素的模拟分析,结果表明当先导通道电荷密度分别呈线性、均匀和指数分布形式时,其模拟的地闪先导电场幅值都随着先导通道高度的增大而趋于稳定,对先导电场起有效作用的是先导通道贴近地面的一定高度内电荷分布且与离通道的距离有关；先导电荷的传播速度对先导电场波形的半峰值宽度有显著影响,而大地相对介电常数同时影响着先导电场波形的幅值和半峰值宽度,且随着相对介电常数值的增大影响逐渐减小,当相对介电常数为20时与理想情况仅仅相差5%。

Study on the characteristics of electric field distribution under the lossy ground condition based on the improved source charge model

Based on the source charge leader model, a model for calculating the leader electric field in the case of lossy ground is established, and the model is validated using artificial lightning detection data. Through the simulation analysis of the influencing factors of the ground conducting field in the case of lossy ground, The results show that when the charge density of the leader channel is linear, homogeneous and exponential, the leader electric field tends to stabilize with the increase of the channel height,the charge distribution of the effective length in the leader channel affects the change of the leader electric field and is related to the observation distance. The leader velocity has great influence on the half peak width of the leader electric field waveform, and has no effect on the leader electric field size. With the increase of relative capacitance, the amplitude of the leader electric field increases and the width of the V-shaped half peak is increased, while the relative capacitance value has little influence(5%) on the amplitude of the leader electric field after 20.