Influence of the Return Stroke Current Waveform on the Lightning Performance of Distribution Lines

An accurate evaluation of the lightning performance of overhead power distribution lines, that is, the evaluation of the expected number of annual flashovers, can be obtained by the application of the Monte Carlo method. In order to reduce the computational effort, a simplified waveform of the channel base current is generally assumed, for example, a linearly rising current with flat top. This paper proposes a Monte Carlo approach able to take into account the typical functions adopted to represent the waveform of the lightning current at the channel base (i.e., the Heidler function and the CIGRÉ function). Moreover, this paper analyzes the effects of different current waveforms on the lightning performance of distribution lines for both direct and indirect strokes.