Computer Modelling and Analysis of Lightning Surges in HV Substations due to Shielding Failure

This paper deals with modelling and analyzing specific transient states of voltages (i.e., of lightning surges in electric power systems of high voltages). The lightning surges arriving in a substation are impacted by more complicated wave effects. Those effects result from a complex spatial structure of each substation, and are determined by all equipment units mounted on it. A model of an electric power line and substation developed for computer software Electromagnetic Transients Program-Alternative Transients Program is presented in this paper. This model includes wave effects and nonlinear effects. It is based on a set of appropriately connected elements (i.e., distributed parameter elements and lumped parameter elements). Furthermore, the analysis results of lightning surges as well as the optimization results of a surge protection system installed in a 110-kV substation are presented in this paper.