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Model and control of a solar tower for energy production

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Detalhes bibliográficos
Resumo:Solar towers are electrical power production systems that use highly concentrated solar radiation as energy source that is collected by means of a heat-transfer fluid. This master thesis studies the application of several control strategies with the aim of maintaining the working fluid at a temperature that maximizes the electrical production. The main difficulties are the nonlinear fluid temperature dynamics, plant thermal constrains, and a variable energy source that cannot be manipulated. The temperature dynamics flow dependence demands for a changing parameter controller that results from a gain scheduling scheme or from a multi-model adaptive control strategy, in which the manipulated variable is adjusted by one of the set of local controllers designed for different operating regimes. The former is accomplished through a Proportional-Integral Controller (PI) control and the latter via Linear Quadratic Gaussian (LQG) optimal control. In addition, the Multistep Multivariable Adaptive Regulator (MUSMAR) control algorithm that adjusts its gains to every plant dynamic change, including parameters, is tested. Although the mentioned control concepts are applied considering the flow as the only manipulated variable, the combination of the latter with the radiation flux reflected by the heliostat field is also studied through PI control. The solar tower electrical power production has a maximum for a given outlet temperature that changes with plant parameters and disturbances. The improvement of production levels is conducted by adjusting the temperature reference with a static optimization procedure.
Autores principais:Kevin, Ramos
Assunto:Solar tower model PI control LQG control MUSMAR Coordination Static optimization Modelo torre solar Controlo PI Controlo LQG Coordenação Otimização estática
Ano:2015
País:Portugal
Tipo de documento:dissertação de mestrado
Tipo de acesso:acesso aberto
Instituição associada:Academia da Força Aérea
Idioma:inglês
Origem:Academia da Força Aérea
Descrição
Resumo:Solar towers are electrical power production systems that use highly concentrated solar radiation as energy source that is collected by means of a heat-transfer fluid. This master thesis studies the application of several control strategies with the aim of maintaining the working fluid at a temperature that maximizes the electrical production. The main difficulties are the nonlinear fluid temperature dynamics, plant thermal constrains, and a variable energy source that cannot be manipulated. The temperature dynamics flow dependence demands for a changing parameter controller that results from a gain scheduling scheme or from a multi-model adaptive control strategy, in which the manipulated variable is adjusted by one of the set of local controllers designed for different operating regimes. The former is accomplished through a Proportional-Integral Controller (PI) control and the latter via Linear Quadratic Gaussian (LQG) optimal control. In addition, the Multistep Multivariable Adaptive Regulator (MUSMAR) control algorithm that adjusts its gains to every plant dynamic change, including parameters, is tested. Although the mentioned control concepts are applied considering the flow as the only manipulated variable, the combination of the latter with the radiation flux reflected by the heliostat field is also studied through PI control. The solar tower electrical power production has a maximum for a given outlet temperature that changes with plant parameters and disturbances. The improvement of production levels is conducted by adjusting the temperature reference with a static optimization procedure.