一种基于传输线方程的埋地电缆电磁脉冲耦合时域分析方法

 埋地电缆和其它金属长导体对核电磁脉冲的耦合分析对于确定合理的工程防护措施具有重要意义。采用Agrawal模型和时域有限差分算法对线缆耦合问题进行了分析，针对该模型中需要计算土壤阻抗与电流项卷积、土壤导纳与电压项卷积的问题，提出了一种土壤阻抗特性的线性拟合处理方法，可避免复杂的卷积计算。介绍了该方法的基本原理和试用结果。这一模型拟合法适用于确定无时域解析表达式的传输线模型参数，与传输线模型的时域有限差分方法相结合，可用于分析非均匀场作用下传输线的耦合。

A time-domain method to calculate EMP coupling of buried cables based on transmission line model

The analysis of the EMP coupling to buried cables is important in EMP protection.Based on the Agrawal model of transmission line and the 1-D FDTD method,this coupling problem is studied.A linear fitting method is proposed to avoid the complicated convolution between ground impedance and transmission line voltage/current.The basic theory and calculation result of the method are introduced.A simple approach is provided to analyze the transmission line model in time-domain considering ground impedance.Comparison of the time domain and frequency domain calculation results shows the proposed method is effective and can solve the coupling problem in non-uniform environment where the frequency domain method does not work.