Medium voltage distribution systems lightning performance estimation

The estimation method for the statistical approach to the number of distribution system insulation failures caused by direct and indirect lightning strikes based on the lightning limiting parameter method is proposed. The optimal computation parameters like computation time-step, the number of strike locations along and perpendicular to the overhead line, and the number of simulations with different lightning current wave-shapes are determined after sensitivity analyses. The reduction of the overhead line flashover rate due to the direct lightning strikes caused by screening effect of the nearby objects is presented.