On Lightning-Induced Voltages in Overhead Lines Over High-Resistivity Ground

This paper presents an improved analytical expression for the calculation of the lightning horizontal electric field considering high values of ground resistivity, which is validated by comparing its results with published results obtained with other methods. The expression is used to calculate lightning-induced voltages in overhead power distribution lines and its results showed that conducted currents injected into the ground by the lightning flash should be considered in the assessment of power line outages, whenever the ground resistivity is higher than 1000 Ω·m. The results also show that, for very high values of ground resistivity, the line length and the ground permittivity affect the lightning-induced voltage peak value, whereas the line height, the return stroke velocity, and the stroke current front-time have negligible effects.