Soil surface potentials induced by Itaipu HVDC ground return current. I. Theoretical evaluation

A methodology for the theoretical evaluation of the solid surface potentials induced in ground return mode, is presented. For each electrode, soil resistivity data acquisition is discussed, giving rise to soil models amenable to mathematical analysis. For one electrode, the soil model considered a slanting interface between the first two layers, empirically considering the influence of a third deeper layer. For the other electrode, the model consists of four different soil layers with horizontal interfaces for which a special numerical approach is used that can be extended to the case of AC induction between parallel wires over multilayer soils