Metodologia de avaliação de integridade das conexões de aterramento de equipamentos a malhas de subestações energizadas

Abstract

Meshes of grounding electrical substations play an very important role both in the functioning of the electrical system and the protection of equipment and people passing over them. Therefore it is essential to know how is the operating condition of this important item after years of being requested by the electrical system and currently due to high incidence of vandalism. This check until recently was done on grids of desenergized substations however nowadays its very difficult to release the plant for hours in order of testing on de-energized conditions. Thus, studies have been performed to propose methods that allow the test of in safe, reliable and fast conditions, with the installation energized Several methods are in use around the world, however, many of them do not require a huge range of equipment, staff and logistics for a reliable execution. This study aimed to compare methods in use and suggest a new methodology to check the continuity of the interconnections between equipment and the mesh of the grounding grid in substation under energized conditions, The propose method support the decision-making regarding the need for intervention in emergency or until scheduled maintenance. This work presents the basic theory of electrical grounding in electric utilities and the steps necessary to design a ground grid along with methods used in de-energized and energized conditions. Finally, we present examples of real applications, with motivations, actions and results.