Evaluation and Performance of Grounding Grids Buried in Soil Under Impulse lightning Current

Abstract

This paper is devoted to analyses the transient behaviour of simple grounding grids under impulse lightning current. The Transmission Line Method (TLM) involving mutual coupling between conductors has been used. The transient behaviour of grounding grids buried in homogeneous and in heterogeneous soil has been evaluated into a complete time domain solution. Several simulations were carried out to study the influence of the electrical energy transport network, the nature of the soil and the location of the current injection point on the voltage level and impedance of the electrical network. Two configurations were presented in this study: in the first the current is in the center of the grid and in the second it is injected into a corner of the two 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. Simulation results obtained show good agreement with those of previous work.