Decreasing grounding resistance of substation by deep-ground-well method

Grounding system is very important to maintain the safe and reliable operation of power network and ensure the safety of power apparatus and operators. A new technique to decrease grounding resistance of substation is presented in this paper, which makes use of deep ground well to decrease the grounding resistance. The ground well is formed by metal tube with water percolation apertures in the soil with groundwater, which has the ability to gather the groundwater and wet the surrounding soil. The principle of deep ground well to decrease grounding resistance is to decrease the resistivity of the soil region surrounding the grounding well by leading the groundwater moving to the deep ground well under pressure, and consequently decrease the grounding resistance of the deep ground well. This novel method was applied in a substation grounding engineering, and good effect was achieved. Index Terms--Deep ground well, grounding electrode, grounding resistance, grounding system, soil resistivity, substation.