FDTD Evaluation of LEMP Considering the Lossy Dispersive Ground

摘要

An accurate evaluation of lightning electromagnetic pulse (LEMP) using the finite-difference time-domain (FDTD) method in 2-D cylindrical coordinates is studied, which takes the soil dispersion into account. The parameters of engineering soil models are reformed by the vector-fitting (VF) scheme, for an efficient handling in FDTD. The FDTD updating equations for the dispersive soil are developed with the semi-analytical recursive convolution (SARC) algorithm. The cylindrical CPML is also developed for truncating the dispersive soil. The efficiency of the proposed method is validated by comparing the numerical results with the Cooray-Rubinstein (CR) approximation. The proposed method provides an accurate FDTD evaluation of LEMP considering the soil dispersion and can be further incorporated into the simulations of more complicated LEMP problems.