Ground-return parameters of submarine cables buried in the seabed

The computation of sea/seabed-return distributed parameters of subsea cables is a relevant topic due to the growing importance of submarine connections. This article presents for the first time new formulas for the computation of self and mutual ground impedances and admittances for submarine cables buried in the seabed. The original theory developed by Sunde is applied to a three-media model with air, sea, and seabed. Referring to the practical installation practice of the Italian transmission system operator Terna S.p.A., we compare the prediction of the available models and assess the effect of the different approximations on the computation of the per unit length ground parameters. Finally, we define the limits of applicability of the available models that differ in accuracy and complexity.