Modeling of lightning and its interaction with overhead conductors

Abstract

Lightning is one of the most powerful and dangerous natural phenomena on the Earth. It has had a profound impact on human society. We will focus here on the so-called "cloud-to-ground" lightning discharges. These discharges can cause damage not only when they strike the structure directly but also when they hit ground nearby. In the case of overhead conductors, whether they are power or telecommunication lines, due to overvoltages produced, these discharges can cause outages, disturbances on the network, or failure of electronic components and/or electrical equipment. In order to mitigate lightning effects via effective technological solutions and protective measures, we need to know lightning parameters and have models of both lightning itself and its interaction with the strike object or system. We will focus on the so-called indirect or nearby lightning and its effects. The following topics will be covered: (1) specification of channel-base current, (2) return-stroke models, (3) calculation of lightning electromagnetic field, and (4) electromagnetic coupling between the lightning channel and overhead conductors. Both analytical and distributed-circuit model (based on generalized telegrapher's equations) approaches will be considered.