Effects of Stratified Soil Structures on Indirect Lightning-Induced Overvoltages in HV and MV Overhead Lines

Indirect lightning strikes represent a significant disturbance for power transmission and distribution networks. Unlike direct strikes, which have been extensively studied, the influence of indirect lightning on overvoltages in high-voltage (HV) and medium- voltage (MV) lines deserve deeper analysis. This paper investigates the impact of two key parameters on bypass voltages: the distance between the strike point and the line, and the soil resistivity (both homogeneous and stratified). The numerical models presented evaluate critical configurations likely to cause flashovers at insulators, compromising service quality. Simulations results show that soil resistivity and strike distance play a major role in overvoltage amplitude.