Lightning - Induced voltages on distribution systems: influence of ground resistivity and system topology

Most of the work on lightning-induced voltages makes reference to single or multi-conductor lines above a perfectly conducting ground. The paper is aimed at showing whether the above simplifications are appropriate for the problem of interest. Distribution systems are, indeed, of different and more complex topology, as they generally consist of one or more main feeder and several laterals, and are situated above a lossy ground. To show whether the mentioned assumptions are appropriate, first the explanation of the mechanism of lightning-induced voltages for the cases of a lossless and of a lossy ground is summarized; then a sensitivity analysis on a H-shaped network is presented, aimed at showing the influence of the presence of the network branches, of the stroke location and of the ground resistivity on the calculated lightning-induced voltages.