基于斜向通道模型的雷电电磁场近场近似特性  

Approximate Characteristics of Lightning Electromagnetic Field in Nearby Area Generated by Oblique Channel

作　　者：王晓嘉[1] 陈亚洲[1] 李冰 万浩江[1] 王琳 

机构地区：[1]军械工程学院静电与电磁防护研究所 [2]63963部队 [3]77108部队

出　　处：《高电压技术》2013年第3期648-654,共7页High Voltage Engineering

基　　金：国家自然科学基金(51077132)~~

摘　　要：为获得更加接近实际情况的近区雷电电磁脉冲场(LEMP)波形,利用偶极子理论对基于斜向放电通道模型产生的地表LEMP场进行了理论研究。通过近似处理,得到了基于TL模型的地表LEMP近场及其导数的一阶、二阶近似解析表达式。采用脉冲函数表示通道基电流,对比了精确表达式与近似表达式计算的电磁场及其导数波形,结果表明:在距回击通道50m以内,电磁场及其导数波形分别与近似电磁场及其导数波形基本符合;在相同距离内,电场与其一阶近似之间的偏差比磁场与其一阶近似之间的偏差小,电场与其二阶近似之间的偏差比磁场与其二阶近似之间的偏差大,且这些偏差都随着水平距离的增加而增加。In order to obtain numerical waveform of lightning electromagnetic pulse（LEMP） close to practical situation,we presented analytical expressions of lightning electromagnetic field on earth surface generated by oblique discharge channel by the dipole method.According to the TL model,we derived the first-order and the second-order approximate expressions of the near field and its derivative.Moreover,using a pulse function to represent the specified channel-base current,we compared the calculation waveforms of the exact expressions and approximate expressions,and it was found that,within a horizontal distance no more than 50 m from return stroke channel,the electric field and its derivative waveforms of the approximate results were essentially coincident with the corresponding waveforms of the exact results.Meanwhile,the deviation between the first-order approximate results and exact results of electric field was smaller than that of magnetic field,but the deviation between the second-order approximate results and exact results of electric field was bigger than that of magnetic field,and all the deviations mentioned above increase with the horizontal distance.

关 键 词：雷电电磁场 斜向放电通道 偶极子法 近似特性 近场 回击模型 

分 类 号：O441.4[理学—电磁学]