Underground Substation Grounding Evaluation Using the Average Potential Method

Electricity is an essential resource of modern life. The commitment to guarantee the supply of electricity to the populations, as well as the lack of space for the allocation of new substations in urban areas are challenges faced by the electricity distribution sector. In order to expand the number of substations to attend the demand, the solution has been to make them underground. For this purpose, this paper aims at evaluating the grounding system for an underground distribution substation using a modified average potential method to ensure the energy supply during faults, as well as to guarantee safety of people in the surroundings. The simulation results show that using the envelope of the substation as a grounding structure should be a promising alternative to dissipate short-circuit currents.