Sistem for interconection of distributed generators to the grid: sintesis of micro grids

Abstract

Distributed generation (DG) systems which employ renewable energy sources as primary source is being encouraged by the Brazilian federal government through agencies such as ANEEL (Brazilian Electricity Regulatory Agency) and the Ministry of Mines and Energy in order to promote solutions to the current problems of energy demand in Brazil. At the same time, the growing concern on the sources with low environmental impact is a factor that promotes the use of these new solutions. Consequently a great number of these sources producing energy in DC form are connected to grid by means of power electronic converters have been subject of intense researches in the academic sphere as well as, in industrial level. In this context, this proposal aims the adaptation of power generation platforms to connect a fuel cell PEM (Proton Exchange Membrane) to grid by means of DC/DC converters and DC/AC voltage source inverters, the management of the energy produced by photovoltaic panels, small wind generators, batteries and ultracapacitors for DC integration and with injection of the extra power into grid as well as, the control and operation of cascaded multilevel converters with constant power flow through the grid, and storage systems (batteries and/or ultracapacitors) and photovoltaic panels (operating close to the point of maximum power) used as primary source. The power converters presented in this approach have to operate in a micro grid in order to obtain maximum capability of energy production, maximum efficiency, currents and/or voltages free of unbalances and distortions and capability to identify islanding situations. Moreover, all control strategies aim the cost reduction of energy production, degradation, and improvement of the life cycle. At the end of this project is expected that the results provide technical information about micro grid operation to the electric companies and researchers in the areas of distributed generation, power electronics, power processing, etc. It is also interest of this project, cooperation public/private, training of undergraduate and graduate students and publication of the research results in peer-reviewed journals in which this proposal is inserted. (AU)