Simplified HV tower grounding system model for backflashover simulation

In this paper the authors present and discuss the application of a lumped parameter model, based on a simple π-type network, which is advantageously usable in lightning performance studies of a typical HV European overhead lines (OHLs). This simplified model is able to simulate tower grounding systems also accounting for non-linear ionization phenomena. The behaviour of the simplified grounding system model is compared with the results provided by using a full circuit model, formerly validated by comparison with experimental tests and with simulation results yielded by field models available in literature. Numerical results show a good agreement between the two models; in addition, the proposed π-network model drastically reduces the computational resources (i.e., memory occupation and execution time) required when complex power systems must be studied in transient and non-linear conditions.