Substation grounding system resistance calculations using a FEM approach

Grounding systems are very important for the safe construction of a substation or a simple building. This paper examines various methodologies for the calculation of different grounding systems, including single rods, rodbeds and grids. In addition, the use of a Finite Element Method (FEM) formulation in the analysis of grounding systems is presented. Both 2D and 3D models are created in order to get an accurate field calculation. Test cases include both uniform and two layer earth structures. The results obtained by the FEM calculations are compared to those obtained by analytical methods, providing useful information about the most suitable methodology for the calculation of the grounding resistance.