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Authors
Abstract(s)
O aumento de gases de efeito de estufa (GEEs), como o dióxido de carbono, causa do
aquecimento global, é consequência da contínua queima de combustíveis fósseis [1]. A
libertação destes gases altera o equilíbrio entre a absorção e emissão de calor pelo
planeta. Por forma a reduzir este fenómeno, a União Europeia pretende até 2050 obter
a descarbonização total de toda a sociedade [2]. Assim, é necessário procurar diferentes
formas, renováveis e sustentáveis, de produção de energia elétrica.
O hidrogénio apresenta-se como uma alternativa viável aos combustíveis fósseis, uma
vez que poder ser combinado com o oxigénio, como numa combustão tradicional, ou para
a produção direta de energia elétrica por meio das células de combustível, sem libertação
de dióxido de carbono. As células de combustível, ou Fuel Cells, são dispositivos
eletroquímicos que convertem a energia química presente nos combustíveis em energia
elétrica e calor. Estes dispositivos possuem uma variedade de aplicações, nomeadamente
na indústria espacial e automóvel, ou em redes DC.
Neste trabalho, pretende-se instalar uma Fuel Cell de 3 kW num barramento DC de 48
V, por meio de um conversor DC-DC. Para tal, elabora-se primeiro um modelo
computacional da célula, recorrendo a ensaios realizados ao dispositivo físico para a
obtenção da curva de polarização e seus parâmetros característicos. Posteriormente, são
apresentados os diferentes conversores DC-DC possíveis de utilizar na instalação, tendose escolhido o conversor Cuk. Analisam-se diferentes estratégias de controlo e
dimensiona-se uma arquitetura em cascata de dois PIDs para o controlo do conversor.
Por fim, são apresentados os resultados experimentais e computacionais que permitem
validar a instalação da Fuel Cell no barramento DC.
The increase in greenhouse gases (GHGs), such as carbon dioxide, cause of the global warming, is driven by the continued burning of fossils [1]. The release of these gases alters the balance between the planet's absorption and the emission of heat. To reduce this phenomenon, the European Union aims to achieve total decarbonization of the entire society by 2050 [2]. Thus, it is necessary to look for different forms of renewable and sustainable electricity production. Hydrogen presents itself as a viable alternative to fossil fuels since it can be combined with oxygen, as in traditional combustion, or to produce direct electrical energy through fuel cells, without releasing carbon dioxide. Fuel cells are electrochemical devices that convert the chemical energy present in fuels into electrical energy and heat. These devices have a variety of applications, namely in the space and automotive industry or DC grids. In this work, the main goal is to install a 3 kW fuel cell on a 48 V DC microgrid, using a DC-DC converter. To achieve this, a computational model of the fuel cell is generated, using tests carried out on the physical model to obtain the polarization curve and its characteristic parameters. Subsequently, the different DC-DC converters that can be used in the installation are presented in this thesis, having selected the Cuk converter for this application. Different strategies of control are analyzed, and a cascade PID architecture is designed to control the converter. Finally, experimental and computational results are obtained to validate the fuel cell installation on the DC bus.
The increase in greenhouse gases (GHGs), such as carbon dioxide, cause of the global warming, is driven by the continued burning of fossils [1]. The release of these gases alters the balance between the planet's absorption and the emission of heat. To reduce this phenomenon, the European Union aims to achieve total decarbonization of the entire society by 2050 [2]. Thus, it is necessary to look for different forms of renewable and sustainable electricity production. Hydrogen presents itself as a viable alternative to fossil fuels since it can be combined with oxygen, as in traditional combustion, or to produce direct electrical energy through fuel cells, without releasing carbon dioxide. Fuel cells are electrochemical devices that convert the chemical energy present in fuels into electrical energy and heat. These devices have a variety of applications, namely in the space and automotive industry or DC grids. In this work, the main goal is to install a 3 kW fuel cell on a 48 V DC microgrid, using a DC-DC converter. To achieve this, a computational model of the fuel cell is generated, using tests carried out on the physical model to obtain the polarization curve and its characteristic parameters. Subsequently, the different DC-DC converters that can be used in the installation are presented in this thesis, having selected the Cuk converter for this application. Different strategies of control are analyzed, and a cascade PID architecture is designed to control the converter. Finally, experimental and computational results are obtained to validate the fuel cell installation on the DC bus.
Description
Keywords
Bateria Célula de Combustível Controlo Pid Conversor Dc-Dc Hidrogénio Matlab Modelização Simulink