Investigation of lightning over-voltages in buried cables based on predicted characteristics of breakdown paths in soils

Assessment of over-voltage in underground power distribution cables, due to lightning strikes impacting the earth´s surface and terminating on the cable, is important in the design of suitable protection schemes and mitigating strategies. Existing models do not account adequately the effect of the characteristics of soil breakdown channels intercepted by the cable. In this paper, over-voltage in underground cable is investigated by considering the effect of the characteristics of soil breakdown paths predicted using a suggested model on an electric-field-related probabilistic basis. The model provides probabilistic information on the over-voltage in struck cables for different soil characteristics and geometrical configurations.