EMTP simulation of lightning overvoltage discharge to medium voltage overhead lines with covered conductors

This paper presents the evaluation and simulation of real lightning discharges that have occurred in medium voltage overhead lines equipped with covered conductors (CC). Lightning stroke current selections are based on real lightning data collected from the Finnish Meteorological Institute (FMI) from 1998 to 2008. The presented feeder is an overhead distribution line with a covered conductor subjected to direct lightning strokes to a line support. With the ATP/EMTP (Alternative Transient Program/Electro-Magnetic Transient Program), simulations of lightning strokes are conducted with different lightning current characteristics. All cases are considered with the modelling guidelines for fast transients, as specified in some lightning literature. Simulations are made to compare the resulting overvoltages and energy absorptions of surge arresters for all the analyzed cases.