Application research on grounding resistance reduction in substation in high soil resistivity area and with limited grounding area

Abstract

This paper introduces the successful application of electrolytic pole in the inclined shafts to reduce the grounding resistance of the original ground grid in order to meet the designed requirements in the reconstruction of an existing substation in high soil resistivity area via the electrolyte generated from the electrolytic pole. The original data of the 500 kV Boluo substation of Huizhou in Guangdong China shows that the ground resistance is 1.05 Ω and soil resistivity greater than 1000 Ω.m. The method involved digging eight inclined shafts with a total length of 1800 m in the periphery of the existing ground grid for the placement of 80 sets of electrolytic pole. Results show that the ground resistance reduces to 0.2013 Ω, a reduced rate of 80.8% after the completion of the reconstruction project. The paper is intended to provide an effective solution for the design and reconstruction of substation in high soil resistivity areas with limited grounding area yet where ground resistance reduction is required. (4 pages)