Model for prediction of characteristics of lightning breakdown channels in soil in the presence of a buried cable

Assessment of damage due to direct lightning strikes on underground cables is important in the design of protection schemes and mitigating strategies. Existing models do not adequately account for the influence of formation of breakdown channels in the soil. In the paper, a two-dimensional model based on electric-field-related probabilities is proposed to predict the formation of breakdown channels and their effect on ground resistance. The influence of lightning current amplitude, geometric configuration and soil parameters has been considered. The model provides a means for complete assessment of the lightning performance of underground cables.