Improvement Of Grounding Resistances Using Adeep-ground-well Method For Indoor-type Substationsrnlocated In Complex Soils

摘要

The purpose of this paper is to investigate the performance of a deep-ground-well method used for improving the grounding resistances of indoor-type substations located in complex soils in the system of Taiwan Power Company (TPC). Three and two ground wells are installed at Kungchia and Kuoan 161/23.9 ～ 11.95kV substations as examples for assessing the improvement. The grounding resistances of ground wells are calculated by one- and equivalent n-layer soil models with the image method and the current distribution electromagnetic grounding and soil structure analysis (CDEGS) program. On the other hand, the grounding resistances of ground wells are measured by the fall-of-potential method. As a result, the calculated grounding resistances of ground wells based on an equivalent two-layer soil model are approximately equal to the measured grounding resistances of ground wells. Moreover, the grounding resistances of Kungchia and Kuoan indoor-type substations after installing ground wells are improved about 70.29 and 58.40%, respectively.