Calculation of fault rates of overhead power distribution lines due to lightning-induced voltages including the effect of ground conductivity

Fault rates in power distribution lines are estimated from probability distributions for induced voltages, obtained through a Monte Carlo simulation of lightning, striking in the proximity of a line over a finitely conductive ground. Waveshapes are presented for various locations relative to the point of interest along the line. The effects of line height, ground conductivity, and return stroke current risetime are analyzed. Results show that the expected number of faults increases for lower ground conductivities