To address the equipment operation and personnel safety hazards caused by excessively high grounding resistance in small substations located in high soil resistivity areas, this study takes a small 220 kV substation in a high soil resistivity region as an example to design and optimize its grounding system model. A deep-well grounding model was constructed using simulation software and the model equivalence method. Key variables such as well depth, equivalent diameter of the well, and resistivity-reducing agents were selected to systematically analyze the effects of the deep well grounding strategy on parameters including grounding resistance, ground potential rise, and contact voltage. The simulation results demonstrate that the proposed grounding resistance reduction strategy meets the design requirements.
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