Investigations of earthing systems under steady-state and transients with FEM and experimental work

In this paper, investigations on the earthing systems with computational method, Finite Element Method (FEM) and experimental work are presented. The earthing systems in this study are of simple built which consist of three earthing systems configurations, 2, 3 and 4 rod electrodes for easy analysis and comparisons. The performance of earthing systems using both simulation and experimental techniques are investigated at power frequency and under transients. It was found that from both FEM and experimental work, the performance of earthing systems under transients is found to be ‘non-linear’ which its non-linearity cannot be neglected. By including the non-linear effect of soil under high currents, more accurate modelling of protective devices and their performance are hoped to be achieved in future.

► We make comparison on performance of earthing systems with experimental work and FEM.
► Performance of earthing systems under lightning is different than that at power frequency.
► Earth resistance values for all earthing systems under transients are lower than that at steady state.
► Close agreement between the results of experimental work and FEM.