A boundary element numerical approach for substation grounding in a two layer earth structure

Abstract

[Abstract] Analysis and design of substation grounding requires computing the distribution of potential on the earth surface (for reasons of human security) and the equivalent resistance of the earthing system (for reasons of equipment protection) when fault conditions occur (Sverak et al.,1981). A new Boundary Element approach for the numerical computation of substation grounding systems in nonuniform soils is presented in this paper. The formulation is specially derived for two-layer soil models, which are widely considered as adecquate for most practical cases. The feasibility of this BEM approach is demonstrated by solving a real application problem, in which accurate results for the equivalent resistance and the potential distribution on the ground surface are obtained with acceptable computing requirements