Estimation on lightning protection performance using a fractal approach

Modeling and estimation of lightning protection systems are very important for the lightning protection design. In this paper, an estimation algorithm on lightning protection performance at 1-m resolution was proposed based on the 3-D dielectric breakdown model (DBM). With the thundercloud model and Laplace´s equation in the space, the DBM model was implemented using a fractal approach. When the tip of the downward stepped leader had reached a height of 100m above the ground, the resolution near the protection device was transformed from 50m to 1m. In the refined estimation area, the leader continued progressing according to the DBM model. Through the application of this approach to estimate the protection performance on a kind of lightning protection system, the cumulative probability distributions in different distances near the lightning protection device could be obtained, and the correlative influencing factors leading to the result were also analyzed.