Electrical stress on the outer insulation of buried cables due to a nearby lightning strike to ground

Field experience indicates that cables buried in soil either directly or in a non-metallic pipe can be at risk due to nearby lightning strike to ground. The triggered lightning experiments provided valuable quantitative information on the subject. There are many questions posed by these observations which motivated a detailed analysis of the electric stress on the cable jacket/sheath, the outer water impervious insulation layer. After identifying the prevailing stress, this work evaluates the dependency of the stress on the associated parameters for the cases of strike to ground and strike to a counterpoise. Possible role of soil ionization is discussed. The role of counterpoise and its protective action are analyzed