Contribuições ao estudo de conversores CC–CC com processamento parcial de potência

• Ano de defesa: 2024
• Autor(a) principal: Santos, Niwton Gabriel Feliciani dos
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; Brasil; Engenharia Elétrica; UFSM; Programa de Pós-Graduação em Engenharia Elétrica; Centro de Tecnologia
• Palavras-chave em Português: Engenharia elétrica (EE); Eletrônica de potência (EP); Processamento parcial de potência (PPP); Processamento de potência ativa e não-ativa; Electrical engineering; Power electronics; Partial power processing (PPP); Active and non-active power processing; CNPQ::ENGENHARIAS::ENGENHARIA ELETRICA
• Link de acesso: http://repositorio.ufsm.br/handle/1/33265

This Ph.D. dissertation provides both conceptual and practical contributions regarding the development of new converters with partial power processing applied to the DC–DC stage of grid-connected photovoltaic (PV) systems and on-board chargers (OBCs) for battery-based electric vehicles, focusing mainly on step-up/down topologies. In short, this technique allows only a fraction of the total active power to be processed by the DC–DC converters, enabling the development of more efficient, smaller, and lighter PV inverters and on-board chargers. This Ph.D. dissertation is essentially composed of articles, which have been accepted/published in national and international journals. In Article 1, a review of the characteristics, configurations, topologies, and applications of DC–DC converters with partial power processing is presented, where the restrictions and requirements for the design of step-up/down topologies are also defined. In Article 2, a step-up/down topology based on the forward converter is proposed, which is applied to the string architecture of a 950-W PV system. In Article 3, a comparative analysis between two H-bridge/push–pull converters with partial power processing applied to the step-up/down DC–DC stage of a 2200-W PV system is proposed. In Articles 4 and 5, a topology based on a reconfigurable full-bridge converter is proposed, which is intended for the step-up/down DC–DC stage of an integrated on-board charger. In this case, a four-winding transformer with an adjustable turns ratio is used, allowing operation in a wide voltage regulation range with high performance in terms of conduction losses. In Article 6, a converter based on a switched-capacitor (SC) circuit for the step-down DC–DC stage of a 3-kW on-board charger is proposed. In this case, the proposed converter does not employ transformers or coupled inductors. However, the capacitors of the SC cell provide the required isolation to prevent a short-circuit between the low and high potentials of the load (battery pack). In Article 7, the Fryze power theory is used to develop a mathematical procedure that culminates in the definition of a single factor for the active and non-active power processed by DC–DC converters, the Fryze power factor: a consistent figure of merit similar to the power factor used in AC systems.