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Abstract(s)
O crescente desafio da necessidade de maiores potências e elevada eficiência nas fontes
de alimentação dos dispositivos e o compromisso de manter regulado o valor dos
harmónicos da rede de alimentação dentro das normas, levou à pesquisa e implementação
de classe específica de retificadores com controlo de fator de potência, que
se caracterizam por não apresentar ponte de díodos completa (bridgeless). Assim,
foi efetuado um levantamento do estado da arte neste domínio, do qual resultou
no estudo teórico e posterior simulação das duas tipologias consideradas mais promissoras,
o retificador Bridgeless Totem-Pole e o Semibridgeless dual boost. Nestas
tipologias, foram também estudadas diferentes estratégias de controlo. No sentido
de confirmar experimentalmente os resultados teóricos e de simulação, foi implementado
um protótipo da Semi-bridgless dual boost a trabalhar em modo de Continuous
Conduction Mode (CCM), com controlo em malha aberta. A técnica de controlo
usada é o Sine Pulse Width Modulation (SPWM), implementada de forma digital
com um microcontrolador. Foi também desenvolvida uma interface gráfica, através
da ferramenta Micrium, que permite ao utilizador interagir e visualizar variáveis do
conversor de potência. De acordo com o dimensionamento efetuado considerando
diferentes cenários de carga, foi possível atingir como melhor resultado um Fator de
Potência (FP) máximo de 98%.
The growing challenge of the need for higher power and high efficiency in power supplies for devices, along with the commitment to maintain the harmonic content of the supply network within regulatory standards, has led to the research and implementation of a specific class of rectifiers with power factor correction control, which are characterized by not having a complete diode bridge (bridgeless). As a result, a review of the state-of-the-art in this domain was conducted, leading to the theoretical study and subsequent simulation of the two most promising topologies, the Bridgeless Totem-Pole rectifier and the Semi-bridgeless Dual Boost. In these topologies, different control strategies were also studied. In order to experimentally confirm the theoretical and simulation results, a prototype of the Semi-bridgeless Dual Boost operating in CCM mode was implemented with open-loop control. The control technique used is SPWM, implemented digitally using a microcontroller. A graphical interface was also developed using the Micrium tool, allowing the user to interact with and visualize the converter’s variables. Based on the design carried out considering different load scenarios, it was possible to achieve a maximum FP of 98%.
The growing challenge of the need for higher power and high efficiency in power supplies for devices, along with the commitment to maintain the harmonic content of the supply network within regulatory standards, has led to the research and implementation of a specific class of rectifiers with power factor correction control, which are characterized by not having a complete diode bridge (bridgeless). As a result, a review of the state-of-the-art in this domain was conducted, leading to the theoretical study and subsequent simulation of the two most promising topologies, the Bridgeless Totem-Pole rectifier and the Semi-bridgeless Dual Boost. In these topologies, different control strategies were also studied. In order to experimentally confirm the theoretical and simulation results, a prototype of the Semi-bridgeless Dual Boost operating in CCM mode was implemented with open-loop control. The control technique used is SPWM, implemented digitally using a microcontroller. A graphical interface was also developed using the Micrium tool, allowing the user to interact with and visualize the converter’s variables. Based on the design carried out considering different load scenarios, it was possible to achieve a maximum FP of 98%.
Description
Keywords
Semi-bridgeless dual boost CCM Power factor Converter AC/DC SPWM Fator de potência Conversor AC/DC