Equivalent lumped parameter II-network of standard grounding systems under surge conditions

The authors propose and validate a simple lumped parameter model based on a π-type network, aimed at simulating the ground potential rise of standard ground electrode configurations under surge conditions. Lumped parameter values are estimated by means of an optimization procedure based on micro-genetic algorithms (μGAs), which minimizes the standard deviation between target values (obtained using a full non-linear circuit model) and simulation results (yielded by the π-network model). The proposed model has been validated by means of massive simulations under surge conditions, i.e. varying impulsive current wave shapes, grounding system geometrical configurations, soil characteristics and also accounting for non-linear ionization phenomena, showing a very good agreement between target values and model results. In addition, the proposed π-network model drastically reduces the computational resources required for linear and nonlinear transient analyses of the simulated grounding systems.