Model Comparison of Voltage-Current Relation for Ionized Soils Produced by Lightning Impulse Current

A physical model of voltage-current relation describes mathematically the non-linear behavior of the soil when it is ionized by the effect of currents flowing through the grounding system. For engineering applications, it is important to understand the non-linear effect of the voltage-current relation in the soil under the influence of ionization. For this reason, mathematical approaches have been formulated to be capable of representing the response of the ionized soil in order to improve the efficiency of grounding systems. In this paper, a comparison of several ionized soil models is presented. A brief description of the models is presented and their voltage-current relation is calculated by simulations using Matlab (R) software. To compare the results provided by the selected models, plots of voltage-current relation are computed and compared (using statistical indicators) with experimental data reported in technical literature. Finally, the main features of the voltage-current plots are analyzed, and a classification of the evaluated ionized soil models is proposed.