Novel method in decreasing grounding resistances of urban substations by utilizing peripheral geographical conditions

A scientific design method was introduced to decrease the grounding resistances of two 110 kV urban substations´ grounding systems in this paper. The first step of the grounding system design process is to gain the soil structure, and the second step is to design the grounding system by numerical analysis according to the multi-layer soil structure model. The peripheral geographical conditions have been taken into consideration to effectively decrease the grounding resistances of substation´s grounding system.