Statistical lightning performance evaluation of overhead distribution lines

Abstract

This paper presents design procedures that achieve specified lightning performance of overhead distribution lines. Since the lightning performance of distribution lines is affected by: (a) pole type and downlead conductor, (b) grounding arrangement, (c) soil resistivity, (d) proximity of trees, (e) arrester placement and (f) lightning activity and lightning parameters of the area, the problem is quite complex. Distribution line lightning performance is distinctly different than overhead transmission lines. This paper presents an integrated model of distribution poles, tower grounding and overhead line conductors. The model is utilized in a Monte Carlo simulation for the purpose of predicting the lightning performance of a distribution line. The paper presents the models and the simulation method. Typical results for typical distribution poles, arrester placement, proximity and height of trees and grounding arrangements are provided. A cost-benefit analysis is also presented that utilizes the results of the simulations towards the most economical design that meets specified performance criteria.