Lightning Response of a Grounding System Buried in Multilayered Earth Based on the Galerkin's Boundary Element and Quasi-Static Complex Image Methods

In this article, we propose a numerical method for accurately simulating the distribution of the lightning current along a grounding grid in a horizontal multilayered earth model. The mathematical model is based on the Galerkin's boundary element method where the quasi-static complex image method and the closed form of Green's function are used for calculations. Furthermore, the effects of the frequency-dependent conductivity and permittivity of the soil are considered. Analytical expressions are also derived for the mutual impedance and induction coefficient. The proposed model can calculate the distribution of the lightning current along a grounding system using the inverse fast Fourier transform and it can be employed to study the transient lightning response characteristics of a grounding grid.