Numerical modelling of lightning surges in high-voltage substations

This paper deals with an issue of modelling and analyzing specific transient states of voltages, i. e. of lightning surges, which occur in electric power systems of high and extra high voltages. It is discussed an electrogeometric theory that can be utilized to estimate the occurrence possibility of overvoltages generated by lightning strokes to phase conductors in overhead power lines. A model of electric power substation is presented; it is developed for computer software EMTP - ATP. This model includes both the wave effects and nonlinear effects. Furthermore, analysis results of the lightning surges are incorporated, as well as optimization results of a surge protection system installed in a 220 kV substation.