Orientador: Jose Antenor Pomilio / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-07T10:48:39Z (GMT). No. of bitstreams: 1 Martins_GeomarMachado_D.pdf: 4129472 bytes, checksum: 7290e97be14c6528a200531ef75ad6b8 (MD5) Previous issue date: 2006 / Resumo: A conexão de fontes de geração distribuída com' a rede geralmente necessita de um conversor eletrônico para processar a energia gerada localmente e injetá-la na rede. Este trabalho apresenta um sistema de geração distribuída para baixas potências, composto por uma fonte primária em CC, como uma Célula a Combustível. Um conversor elevador boost conecta a fonte primária a um inversor trifásico comutado em baixa freqüência que injeta a energia na rede e garante a sua qualidade. Um circuito auxiliar é agregado à topologia do inversor com a finalidade de reduzir a distorção de sua tensão de saída, dessa forma melhorando a forma de onda da corrente. A estratégia de controle empregada permite um desempenho seguro mesmo com as flutuações na energia gerada. As principais vantagens desta proposta são a minimização das perdas de chaveamento (ou seja, alto rendimento) e a eliminação de IEM (o que evita o uso de filtros de altas freqüências comuns nos conversores chaveados em alta freqüência). Os procedimentos de projeto são estabelecidos com vistas à redução do volume dos elementos empregados no circuito, buscando uma densidade de potência mais alta. Um protótipo de 1300 V A é implementado e testado. Os resultados obtidos confirmam a análise teórica / Abstract: The connection of distributed power sources with the utility grid generally needs an electronic power converter for processing the locally generated power and injecting current into the system. This work presents a system intended to low-power distributed generation composed by a DC primary source, as a fuel cell. A boost converter connects the supply to an inverter, composed by a three-phase one using low-frequency commutation, which injects the power into the grid and guarantees the AC power quality. An auxiliary circuit is added to the inverter topology in order to reduce the output voltage distortion, thus improving the current waveform. The employed control strategy allows a secure performance even if there are fluctuations in the generated power. The main advantages of this approach are the minimization of the switching losses (i.e. high efficiency) and the elimination of the EMI (which avoids high-frequency filters necessary in high-frequency commutation inverters). Design procedures are established permiting to reduce the volume of the elements, seeking a high power density. A 1300 V A converter prototype is implemented and tested. The obtained results confirm the theoretical analysis / Doutorado / Energia Eletrica / Doutor em Engenharia Elétrica

The current shift towards renewable energy resources creates volatility in the electricity production that must be compensated by nevi sources of balancing energy. To ensure a normal operation of the power system, the transmission system operators procure power reserves able to provide regulation energy through market processes. Virtual power plants are now likely to participate on the balancing markets. In this study, the technical and economic feasibility of having virtual power plants participate in the Swiss balancing market is assessed. The study begins with the evaluation and compa.rison of four European balancing market designs and continues with the clarification of the concept of virtual power plant. The focus is then set on the Swiss ancillary services market, recently open to virtual pmver plants. After a detailed market description, an economic model simulating the participation of a virtual power plant made of industrial resources on the secondary and tertiary control markets has been developed. This model \Vas evaluated on an actual market design: the Sv.riss ancillary servicel:l market. 5 cases were simulated, allowing to estimate the opportunity fom both the capacity and the energy market productl:l. The simulations indicated that an example company (based on an actual situation) could hope a decrease in its energy cost between :3 and 4% by participating in a control pool over a year. Other simulations demonstrated the greater profit expected from secondary reserves compared to tertiary rel:lerves, and the need to develop an automatized activation system. The encouraging economic study is followed by a technical overview of the envisioned system. A generic technical characterization of virtual power plant is presented, on v.rhich the Swiss use-case is later applied. The breakdown into functional requirements allowed to highlight specific issues. The design of the control strategy, particularly to deliver secondary control, as well as the hardware communication interface to use are tvw aspects that ,vill require further analysis. Additionally, on an economic level, the investment cost for remote communication modules are acceptable with respect to the economic potentials estimated in the first part, for medium­sized industrial energy resources. In conclusion, the study established the profitability of an aggregation project on the Swisl:l market but also demonstrated the need to pursue research for the project to be fully feasible on a technical level.