分层土壤结构下雷电感应过电压计算与分析  

Calculation and Analysis of Lightning Induced Overvoltage with Stratified Ground Structure

作　　者：汤霄 张其林[1,3] 李东帅[1,3] 张亮[1,3] 高金阁[4] 

机构地区：[1]南京信息工程大学气象灾害预报预警与评估协同创新中心中国气象局气溶胶与云降水重点开放实验室,南京210044 [2]中国石化华东分公司,南京210019 [3]南京信息工程大学大气物理学院,南京210044 [4]北京市气象局,北京100089

出　　处：《高电压技术》2015年第1期84-93,共10页High Voltage Engineering

基　　金：国家自然科学基金(41375037;41275009);公益性行业(气象)科研专项(GYHY201306069)~~

摘　　要：为研究雷电感应过电压的发展规律,为架空输电线路的防雷设计提供有价值的参考依据,开发了雷电感应过电压3维时域有限差分(3-D FDTD)算法。利用该算法,研究了不同分层土壤结构对架空输电线路雷电感应过电压的影响。对于水平分层土壤,当上层土壤电导率(0.001 S/m)明显小于下层(0.1 S/m)时,土壤等效阻抗变化带来的影响使感应过电压幅值与上层土壤厚度呈正相关;反之,感应过电压幅值则随上层厚度的增大急剧减小,厚度>2 m时其幅值几乎仅由上层土壤决定。对于垂直分层土壤,当雷电电磁场由高电导率土壤传播至低电导率土壤时,垂直分层结构对耦合电压的影响不容忽略;反之,若线路附近5 m以上区域存在高电导率土壤时,则不需考虑垂直分层结构的影响。综上,在架空输电线路雷电感应过电压计算中,需要根据实际情况决定是否考虑分层土壤结构(包括水平分层和垂直分层)的影响。In order to understand the development law of lightning induced overvoltage and to provide references for lightning protection design, we developed a three-dimensional finite-difference time-domain （3-D FDTD） method. Using this method, we analyzed the relationship between stratified conducting ground and lightning-induced overvoltage. In the case of horizontally stratified ground, when the conductivity （0.001 S/m） of the upper layer is much lower than that of the lower layer （0.1 S/m）, the induced voltage peak is positively correlated with thickness of the upper layer due to the influ- ence of equivalent ground impedance. However, the voltage peak decreases sharply with increasing depth of the top layer when the conductivity of the top layer is interchanged with that of the second layer, and the peak value is almost solely determined by the top layer if its depth is over 2 m. In the case of vertically stratified ground, when lightning electromag- netic field propagates from the layer with higher conductivity to one with lower conductivity, the effect of the stratified ground can not be ignored. However, the vertically stratified structure can be ignored if the section in more than 5 m from a transmission line has conductivity high enough. It is concluded that whether to take the influence of stratified earth （in- cluding horizontally and vertically stratified structure） on the lightning induced overvoltage into consideration depends on the practical situation.

关 键 词：架空配电线路 雷电电磁场 回击 雷电感应过电压 3维时域有限差分算法 分层土壤 

分 类 号：TM863[电气工程—高电压与绝缘技术]