Lightning-Induced Overvoltage Peaks Considering Soil Parameters Frequency-Dependence: New Approach with Dominant Frequency Associated with Lightning Current Front Time

For the study of lightning performance of distribution lines, the correct assessment of indirect flashes plays an important role. Thus, this paper considers the frequency-dependent soil electrical parameters in a previously developed approximate formula for the peak value of lightning-induced overvoltage on overhead lines. This approach consists of using a specific frequency (based on the lightning front time) to estimate the ground conductivity. Since the proposal is easy to implement and fast to run in any computational environment, it is a practical engineering tool. According to the results, it is possible to note the importance of applying models that take into account the variation of soil parameters with frequency, since overvoltage reductions for high resistivity soils above 35% were verified.