Earth surface voltages at a grounding system of buried grid and rods from the fast Galerkin´s moment method

The fast Galerkin´s moment method is used to calculate the resistance and the surface voltages of power network grounding systems which consist of a grid and rodbed. Each conductor in the grounding system is considered as one segment. The outgoing current from each conductor is assumed to be uniform along the conductor. The accuracy of the resistance calculation is very high. However, for surface voltage calculations, the voltage at the boundary has to be satisfied to yield high accuracy. In the present paper, the authors have proved that no more than two extra segments at the end of each conductor are needed to correct for the assumed current distribution. This modification yielded accurate surface voltage, with average error <5%