Efficient analysis of grounding systems by means of the hybrid FEM-DBCI method

In the design of a grounding system, technical and normative constraints have to be met. Therefore, it is necessary to use a tool that is able to accurately estimate the values of the significant parameters of the grounding system, such as earth resistance and touch-and-step voltages. The computation of such quantities calls for the solution of a 3-D open-boundary static electromagnetic field problem, which should take into account the nonhomogeneous structure of soil. The hybrid finite-element method–Dirichlet boundary condition iteration method is applied to the solutions of such problems. A great advantage of this method is that it directly provides the electric potential distribution on the earth surface as part of the solution. Some grounding systems are analyzed, and the comparisons of the results with those obtained by other methods are made.