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

The article presents the analysis of the transient behaviour of grounding grids subjected to impulse lightning current. The TLM including mutual coupling between conductors will be applied. The transient behaviour will be assessed into complete time domain solution by entombing under homogeneous and stratified soil. 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. The current is going to be injected twice. Firstly, in the center of the grid. Secondly, in one cormer of the two configuration. Comsequently, the lowest transient potential displays in the grid 1x1 when the injuction point is in the lower resistivity. Whereas the better behaviour is shown in the grid 2x2 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.