Soil ionization in different types of grounding grids simulated by FDTD method

The main goal of this work is to analyze the soil ionization effects in different types of grounding grids. The analysis was performed by implementing a software based on the FDTD method, for modeling the non-linear behavior of the ground due the application of high intensity lightning currents. Step voltages on the soil surface were calculated from the border of the grounding grid to a point 1 m away from it. The ionization influence is determined by comparing the results to data obtained by modeling linear ground. The obtained results are physically consistent.