New functions for representing IEC 62305 standard lightning currents

The parameters of the new function for representing lightning currents from the international standard IEC 62305 are given in this paper for the first positive, first negative and subsequent negative short stroke currents, so as for the long stroke current. It can be used also for the superim-posed positive or negative short stroke currents. Results for lightning electromagnetic field at different distances from the channel-base, obtained by using such channel-base current and Modified transmission line model with exponential decay as an engineering model, are compared to the results from literature.