Distributed substations: an innovative low impact solution

Abstract

While searching for solutions to minimize environmental impact of substations and improve efficiency in services by optimizing costs, AES Eletropaulo promoted an R&D project to implement smaller substations, which are operationally integrated with feeders and amongst each other, in such a way as to optimize power reserve capacity. ENERQ/USP, ABB and Themag, were invited to take part in this project, thus establishing an attractive partnership in which the utility describes the problem, criticizes alternatives and evaluates application feasibility; the University researches and shapes solution proposals; the Manufacturer develops proposals and equipment and; finally, the designer materializes the solution. This article presents the methodology and the results obtained, and describes solution implementation in a pilot area. Methodology involves an innovative method in the evaluation of substation alternatives, which contemplates objective issues in direct manner, and intangible issues through structured specialist analysis. Analysis of the grid, which functions as "distributed substation" "interconnection bus", allowed for optimum location of re-connectors and maneuver switches, maximizing continuity and operational ease. The pilot project is being implemented in the region of Cotia, Sao Paulo, where strong environmental restrictions prevent penetration of high voltage lines within load center and 34.5 kV power is available at neighboring substations.