The lightning-surge proofness of UHV overhead lines

The main difficulties of lightning protection system design are in the very small amount of statistical data, obtained from service experience, on the one hand, and the absence of reliable computing methods, intended for prediction of lightning-surge proofness, on the other. This paper presents some investigations of the lightning-surge proofness of UHV overhead lines. There are data on the electric strength of insulating suspensions, statistics of lightning break out into different line elements, probability of lightning outbreak through shielding wires to conductors and characteristics of impulse streamer corona on line conductors. The physical and numerical models of lightning descending leader orientation towards grounded objects were created.