Impulse response of grounding grids: Experimental versus simulated results

The experimental and simulated responses of a grounding grid, comprising 20 4-m-×-4-m meshes buried in a 160-Ωm soil, subjected to currents with lightning-patterned waveforms were determined. Simulations considered assumptions of constant and frequency dependent soil resistivity and permittivity. The amplitude and waveform of the measured and simulated grounding potential rise were quite similar and, due to the low value of soil resistivity, the frequency dependence of soil parameters practically did not affect the results.