Armazenamento de energia associado à produção com origem em fontes renováveis

Nos últimos anos, o setor elétrico tem vindo a passar por profundas transformações. Estas são devidas aos avanços tecnológicos e alterações do tipo de cargas, maiores exigências ao nível da qualidade de energia, liberalização do mercado em curso, grandes preocupações com as questões ambientais sobretudo ao nível da produção, proliferação da geração distribuída, os clientes passaram a adotar uma postura exigente ao nível dos produtos e serviços, crescimento da procura da energia elétrica. Na tese desenvolve-se uma abordagem baseada na geração distribuída com armazenamento de energia, tendo em consideração as oportunidades que a evolução do setor elétrico pode vir a contemplar. As oportunidades ao nível do consumidor com capacidade de produção que poderá contribuir de forma ativa para o funcionamento mais eficiente de todo o sistema elétrico. Esta contribuição estará ao nível de uma gestão de carga mais flexível que permitirá evitar ou adiar novos investimentos ao nível da produção, transmissão e distribuição de energia. Acrescentando-se o armazenamento de energia nas instalações finais, o sistema energético do cliente vai poder gerir as trocas com a rede, estando disponível para prestar serviços auxiliares à gestão da rede através da resposta a pedidos de auxílio por parte do gestor da rede, no sentido do fornecimento de energia/deslastre de cargas ou para aumento das carga/armazenamento de energia. Passa a atuar aproveitando as oportunidades de negócio em troca do auxílio à rede, ou seja, de uma prestação de serviço. Neste sentido foi desenvolvido nesta tese um modelo de gestão do fluxo de energia entre produção, carga na habitação, armazenamento e rede pública permitindo ao consumidor tirar benefícios económicos do seu sistema produção com armazenamento. Por outro lado, a rede elétrica beneficia com a diminuição das perdas ao nível da transmissão e distribuição, mas sobretudo com a flexibilidade da carga que lhe resolve problema nos períodos de ponta até em períodos em que há excesso de energia para distribuir. Além disso, com a existência deste tipo consumidor com sistema inteligente de gestão de energia, conseguem-se evitar ou adiar investimentos na atualização das redes para satisfazerem a procura. O modelo de gestão de energia que é aqui apresentado permite gerir as correntes das diferentes fontes num barramento DC nas instalações finais de clientes residenciais ou comerciais. A gestão é feita através de conversores DC/DC aplicados entre as diferentes fontes DC e o barramento DC, sendo controlada a corrente que está disponível na saída de cada uma delas em especial dos elementos de armazenamento. A utilização da rede DC permite uma gestão mais eficiente da produção com base em fontes de energia renováveis, evitando-se perdas nas conversões AC/DC e DC/AC nas trocas com a rede AC, além disso facilita a gestão dos fluxos de energia entre os diversos elementos do sistema. Entre o barramento DC e a rede AC existe um inversor que é responsável por promover as trocas nos dois sentidos através da leitura da tensão existente no barramento DC. Assim se a tensão no barramento DC descer um pouco, vai trazer a energia de AC para DC e no caso da tensão no barramento DC subir um pouco, a energia passa do barramento DC para a rede AC. Atualmente no regime português de auto consumidor a injeção de energia para a rede é pouco compensador, ou perde-se a energia quado não há contagem ou existindo contagem é vendida a um preço baixo muito inferior ao da compra de energia. Mas espera-se que constantes mudanças regulatórias e de mercado da energia elétrica, levarão certamente no sentido dos atuais consumidores/produtores poderem vir a prestar serviços à rede elétrica pública e obterem com eles novas formas de remuneração, que contribuirão para reduzir a sua fatura energética. In recent years, the electricity sector has been undergoing profound changes. These are due to technological advances and changes in the type of loads, greater demands on power quality level, the ongoing market liberalization, major concerns with environmental issues particularly in terms of production, proliferation of distributed generation, customers have adopted a demanding posture in terms of products and services, growth in demand for electricity. The thesis develops an approach based on distributed generation with energy storage, taking into account the opportunities that the evolution of the electricity sector can come to contemplate. The opportunities at the consumer level with a production capacity which can contribute actively to the more efficient operation of the entire electrical system. This contribution will be the level of a more flexible load management that will avoid or postpone new investments in the production, transmission and distribution of energy. Adding energy storage in the final installation, the energy system of the customer will be able to manage exchanges with the network and is available to provide ancillary services to the management of the network by responding to requests for assistance from the network manager, the sense of power supply / shedding loads or increase in load / energy storage. Now operates taking advantage of business opportunities in exchange for aid to the network, ie the provision of service. In this sense it was developed in this thesis a model of management of energy flow between production, load housing, storage and public network, enabling customers to get economic benefits from its production system with storage. On the other hand, the power grid benefits from the reduction in losses in terms of transmission and distribution, but above all with the flexibility of the load that solve problem during peak periods even in periods when there is excess energy to distribute. Moreover, the existence of this consumer type with intelligent power management system, can be avoided or postpone investments in upgrading networks to meet demand. The power management model that is presented here allows manage the currents of different sources in a DC bus in the final installations of residential or commercial customers. The management is via DC/DC converters applied between different DC source and the DC bus and is controlled current which is available at the output of each especially of storage elements. The use of the DC bus allows more efficient management of production based on renewable energy sources, avoiding losses in conversion AC/DC and DC/AC in trade with the AC grid also facilitates the management of energy flows between the various elements of the system. Between the DC bus and the AC grid, there is an inverter that is responsible for promoting the exchange in both directions through the reading of the tension on the DC bus. So if the voltage on the DC bus down a little, will bring the power of AC to DC and in the case of DC bus voltage rise slightly, the energy passes from the DC bus to the AC grid. Currently the Portuguese system auto consumer injection into the grid is unrewarding or energy is lost there is no count or count there is sold at a low price much lower than buying energy. But it is expected to constant regulatory changes and the electricity market, will certainly lead towards the current consumers / producers can come to provide services to the public power grid and achieve with them new forms of remuneration, which will help reduce energy bill .In recent years, the electricity sector has been undergoing profound changes. These are due to technological advances and changes in the type of loads, greater demands on power quality level, the ongoing market liberalization, major concerns with environmental issues particularly in terms of production, proliferation of distributed generation, customers have adopted a demanding posture in terms of products and services, growth in demand for electricity. The thesis develops an approach based on distributed generation with energy storage, taking into account the opportunities that the evolution of the electricity sector can come to contemplate. The opportunities at the consumer level with a production capacity which can contribute actively to the more efficient operation of the entire electrical system. This contribution will be the level of a more flexible load management that will avoid or postpone new investments in the production, transmission and distribution of energy. Adding energy storage in the final installation, the energy system of the customer will be able to manage exchanges with the network and is available to provide ancillary services to the management of the network by responding to requests for assistance from the network manager, the sense of power supply / shedding loads or increase in load / energy storage. Now operates taking advantage of business opportunities in exchange for aid to the network, ie the provision of service. In this sense it was developed in this thesis a model of management of energy flow between production, load housing, storage and public network, enabling customers to get economic benefits from its production system with storage. On the other hand, the power grid benefits from the reduction in losses in terms of transmission and distribution, but above all with the flexibility of the load that solve problem during peak periods even in periods when there is excess energy to distribute. Moreover, the existence of this consumer type with intelligent power management system, can be avoided or postpone investments in upgrading networks to meet demand. The power management model that is presented here allows manage the currents of different sources in a DC bus in the final installations of residential or commercial customers. The management is via DC/DC converters applied between different DC source and the DC bus and is controlled current which is available at the output of each especially of storage elements. The use of the DC bus allows more efficient management of production based on renewable energy sources, avoiding losses in conversion AC/DC and DC/AC in trade with the AC grid also facilitates the management of energy flows between the various elements of the system. Between the DC bus and the AC grid, there is an inverter that is responsible for promoting the exchange in both directions through the reading of the tension on the DC bus. So if the voltage on the DC bus down a little, will bring the power of AC to DC and in the case of DC bus voltage rise slightly, the energy passes from the DC bus to the AC grid. Currently the Portuguese system auto consumer injection into the grid is unrewarding or energy is lost there is no count or count there is sold at a low price much lower than buying energy. But it is expected to constant regulatory changes and the electricity market, will certainly lead Tese: Armazenamento de Energia Associado à Produção com Origem em Fontes Renováveis Doutoramento em Engenharia Eletrotécnica e de Computadores da FCTUC viii towards the current consumers / producers can come to provide services to the public power grid and achieve with them new forms of remuneration, which will help reduce energy bill