A Full-Wave PEEC Model of Thin-Wire Structures above the Lossy Ground

This article addresses a full-wave partial element equivalent circuit (PEEC) model of wire structures above a lossy ground (LSG) for lightning transient analysis. The PEEC model is formulated with dyadic Green's functions. An equivalent circuit is derived for the first time by including correction terms arising from the LSG. Circuit parameters are expressed using Sommerfeld integrals, which can be evaluated numerically and be presented with lookup tables. The low-frequency model of the LSG is derived, and is depicted using the mirror image of source elements, similar to the case of a perfect ground. The comparison of circuit parameters calculated with this model and the Sommerfeld integrals is made. The proposed method is validated numerically with the numerical computation code in the frequency domain, and the finite-difference time-domain (FDTD) method in the time domain. Good agreements are observed. The proposed method is then applied to analyze lightning transients in a wire structure over the LSG. It is concluded that the LSG can be substituted with the low-frequency model for transient analysis. The computational burden in the time-domain simulation can be significantly relieved.