Lightning performance and protection systems

The lightning performance measures how many lightning faults per year a system experience as a function of its insulation level, i.e. the probability that the line is subject to an overvoltage greater than its Critical-Flash-Over voltage (CFO). · Direct lightning strikes to power distribution lines cause insulation flashover in the great majority. · Indirect strikes are more frequent and, in presence of tall structures can occur even at very close distances to the line. · In low insulation systems, they represent one of the most significant causes of lightning-related outages