Calculation of Transient Currents in Grounding Systems Using Antenna Theory-Based Models

This paper presents a mathematical model for the calculation of transient current distribution in grounding systems, based on antenna theory. The modeling of grounding electrodes relies on a system of coupled integro-differential equations of the Pocklington type, applied to complex wire structures buried in a semi-space with finite conductivity. The Pocklington equation is derived directly from Maxwell’s equations, and the paper thoroughly describes the entire procedure, including the influence of the boundary between two media using Fresnel reflection coefficients. The system of equations is solved using the indirect boundary element method, resulting in the determination of current distribution along grounding structures of various geometries, which represents a fundamental parameter for analyzing the transient response of grounding systems.