Evaluation of Ground Parameters on Lightning-Induced Over-Voltages Considering Various Return Stroke Models

The modeling of a lightning return stroke is the most widely discussed topic in the domain of electromagnetic compatibility. In this article, we present a comparative analysis of various engineering return stroke models, namely, transmission line type and travelling current source type models, respectively, on lightning-induced overvoltages over a lossy ground. These models describe the spatial and temporal distribution of the lightning return-stroke current along the lightning channel. A sum of Heidler functions is adopted to characterize the lightning return-stroke current. The finite-difference time-domain approach is used to compute the electromagnetic fields for a finitely conducting ground. Then Agrawal's coupling model is adopted to compute the incident and the scattered components of the voltages and correspondingly their resultant, that is, lightning-induced overvoltages. The impact of these models is analyzed on peak values, rise-time, and the decay characteristics of lightning-induced overvoltages for various ground configurations.