A BACKFLASHOVER MODEL FOR CALCULATING THE TRANSMISSION LINES ’ LIGHTNING PERFOMANCE

The paper presents a model, which determines the probability of backflashover in high voltage transmission lines due to lightning strokes, using Monte-Carlo simulation. The model can estimate the average number of faults which may occur in a transmission line by dividing them in single phase and three phase faults. Furthermore, the average grounding resistances of the transmission lines are calculated. The developed model was applied, on several operating Greek transmission lines, giving satisfactory results. The proposed model can be used as a useful tool in the design of electric power systems, aiding in the right insulation dimensioning of a transmission line.