Numerical simulation of a grounding grid buried in horizontal multilayered earth based on ‘T’ typical basic elements in the frequency domain

In this study, the authors propose a new mathematical model that allows the accurate computation of currents flowing through a substation´s grounding grid buried in horizontal multilayered earth, which is a hybrid of Galerkin´s method of moment and the conventional nodal analysis method based on `T´ typical basic elements. The dynamic state complex image method and the closed form of Green´s function of a horizontal dipole or monopole in the earth model are introduced into this mathematical model to enhance its efficiency. In addition, an analytical formula for mutual induction and impedance coefficient calculations are used to accelerate the application of this method. Finally, some numerical results related to a practical grounding problem are discussed and some conclusions are given.