地表垂直分层条件下倾斜通道雷电电磁场特性研究  

Characteristics of Lightning Electromagnetic Fields from Oblique Lightning Channel Considering Vertical Stratified Ground

作　　者：王晓嘉[1] 陈亚洲[1] 万浩江[1] 王李鹏[1] WANG Xiaojia CHEN Yazhou WAN Haojiang WANG Lipeng(Key Laboratory on Electromagnetic Environment Effects, Ordnance Engineering College, Shijiazhuang 050003, Chin)

机构地区：[1]军械工程学院电磁环境效应国家级重点实验室,石家庄050003

出　　处：《电子与信息学报》2017年第2期466-473,共8页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(51377171)~~

摘　　要：为了得到垂直分层大地电导率和雷电回击通道倾斜角度对雷电电磁脉冲场(LEMP)的影响规律,该文利用时域有限差分法对倾斜通道雷电电磁场进行了建模计算。研究结果表明,当观测点位于倾斜回击通道下方时,地表雷电电磁场峰值会随着回击通道倾斜角度的增加而出现明显的上升,同时电磁场的上升沿变得更加陡峭。观测点与地表雷击点之间的水平距离越大,雷电电磁场的峰值时间也就越大。对地表电磁场而言,观测点同侧大地电导率主要影响雷电水平电场和角向磁场的初始峰值,而观测点另一侧大地电导率的变化则主要影响水平电场和角向磁场波尾幅值。对地下电磁场而言,增加埋地深度对垂直电场的衰减作用十分明显,而对水平电场和角向磁场来说影响极小。The electromagnetic fields from oblique lightning channel are studied by using FDTD and considering the effects of vertical layered ground conductivity and lightning channel tilt angle. The calculation results show that the initial peak values of lightning electromagnetic fields will increase with increasing the channel tilt angle when the observation point is under the oblique lightning channel, and the rising edges of the electromagnetic fields become steeper. The peak time of the lightning electromagnetic fields will be greater with greater distance between the lightning stroke point on the ground and the observation point. For the electromagnetic fields on the ground surface, the ground conductivity at the same side of the observation point affects mainly the initial peak values of the horizontal electric field and azimuthal magnetic field; the ground conductivity at the other side affects mainly the amplitudes of the wave tail of the horizontal electric field and the azimuthal magnetic field. For the electromagnetic fields inside the ground, the vertical electric field will decrease with increasing the underground depth, but the horizontal electric field and azimuthal magnetic field underground is basically the same as that on the ground surface.

关 键 词：雷电电磁脉冲场 时域有限差分法 分层大地电导率 倾斜放电通道 倾斜角度 

分 类 号：O441.4[理学—电磁学]