Development of an improved earthing method for power and distribution transformers substations

Abstract

Engineers and planners have realized that equipment grounding is a necessary part of installation process in Electrical power substations. Over years, grounding or earthing has been carried out primarily through preparation of Earth Mat which is interconnected with several Earth-rods buried around the equipment under consideration. This approach takes several efforts to have an acceptable and reliable result. However, this paper presents a more flexible, economical and results oriented approach. A flow chart which describes the procedures of carrying out the proposed method of earthing is developed. This was applied to two case studies: a proposed Power transformer substation and distribution Transformer substation located within the same geographical domain. On the two cases, the measured earth resistances are presented and discussed. The results from the case study indicates that the earth resistance values obtained from this new approach are reliable and in compliance with IEEE Standards 80,142, 81 and 1100.