Lightning Performance of Unshielded Transmission Lines

This paper presents further analyses of stodiesof the lightning performance of unshielded transmission lines by direct strokes, which were made using a developed Monte-Carlo and dynamic travelling wave program. The more important factors affecting the lightning performance as exhibited by the calculations are discussed. This led to the recognition of the basic requirements to achieve good lightning performance for such unshielded lines. A preliminary economical 33kV unshielded line design achieving these requirements is also offered.