Recapacitação e renovação de subestações: aspectos relacionados a equipamentos, confiabilidade e arranjo físico

Abstract

Aging and obsolescence are factors that occur throughout the Brazilian electrical system, which is why the modernization of substations is inevitable. It is important to highlight that the electrical systems in Europe and in Japan have gone through this process in recent years, and it is inevitably already taking place in the National Interconnected System – NIS. Substations must also be renewed when the network parameters (short circuit current, rated current, voltage, etc.) change. This is due to changes in the transmission network, or when you want to improve the substation's reliability. The adoption of new project assumptions, specially in the electricity sector, faces several barriers in the market, whether due to lack of knowledge of the technology, to public notice requirement or to project standardization. During the circuit breaker technology upgrade process, for example, the design engineers probably encountered the same difficulties. When faced with the need to upgrade the substation or the need to replace equipment, an engineer with little experience will probably specify equipment equal to the existing one, without making a more accurate analysis of the subject, considering a long-term horizon and new technologies. This work aims to propose a methodology for assessing the need and/or the convenience of carrying out the refurbishment of transmission substations (known by the terms: uprating and upgrading), through a case study, highlighting the main points that should be observed by all professionals involved in the project, supporting the expansion and planning of such systems with relevant decisions.