Analysis of the performance of grounding grids buried in heterogeneous soil under impulse current

Abstract

The present paper is devoted to analyzing the transient behaviour of simple grounding grids subjected to impulse lightning current. The transmission line method (TLM) involving mutual coupling between conductors will be used. The transient behaviour of grounding grids buried in homogeneous and in heterogeneous soil is going to be evaluated into a complete time domain solution. Different simulations carried out altering, the influence of the grid dimensions, the kind of the ground and the current injection point on the grid voltage and impedance will be presented. Simulation results will be shown for two extreme cases: in the first case the current is in the center of the grid and in the second one it is injected in one corner of the two configurations of grids. The obtained results show that the grid 1x1 gives the lowest transient potential when the injection point is in lower resistivity side, and the grid 2x2 presents better behavior when the current is injected at center point. It is obvious that the suggested simulations are in a good agreement, with corresponding results of other researchers.