Proposta de nova topologia com número reduzido de chaves para inversor de sete-níveis alimentado por duas fontes de tensão contínua assimétricas não isoladas

• Ano de defesa: 2017
• Autor(a) principal: Meier, Martin Breus
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Tecnológica Federal do Paraná; Curitiba; Brasil; Programa de Pós-Graduação em Engenharia Elétrica e Informática Industrial; UTFPR
• Palavras-chave em Português: Inversores elétricos; Eletrônica de potência; Conversores de frequência; Máquinas elétricas; Disjuntores elétricos; Engenharia elétrica; Electric inverters; Power electronics; Frequency changers; Electric machinery; Electric circuit-breakers; Electric engineering; CNPQ::ENGENHARIAS::ENGENHARIA ELETRICA::SISTEMAS ELETRICOS DE POTENCIA::CONVERSAO E RETIFICACAO DA ENERGIA ELETRICA; Engenharia Elétrica
• Link de acesso: http://repositorio.utfpr.edu.br/jspui/handle/1/2783

Multilevel inverters can benefit from reduced output filters due to the lower harmonic content of the synthesized signal, since their outputs have lower voltage differences during their switching. Its disadvantage is caused by the high number of controlled switches and its auxiliary circuits normally required for its operation. In order to reduce the number of switches used in a seven-level inverter, a new topology for a seven level and its auxiliary circuits inverter is presented, constructed from two asymmetrical voltage sources connected in series and six semiconductor switches. This work analyzes the principles of operation of this topology and the switching logic required for its operation. The proposed arrangement does not offer the possibility of voltage reduction on the switches, as presented in the classical inverters topologies with diode or capacitor clamping or the series connected cells, but it reduces the amount of components necessary for the composition of the seven levels, being possible to use it in low voltages inverters, due to its smaller size and complexity. The study presents the resulting structure in the form of a single-phase inverter, using the pulse-width modulation with phase-contrast carriers technique, with seven equally spaced levels, using only six switches and two voltage sources with asymmetrical voltages, in which the main source has double the voltage of the other. The operation of the topology is checked with simulation and an implementation of a 860W prototype. Another version is also presented analytically, with better voltage clamping, using eight keys controlled with a more simplified logic. Finally, some proposals are suggested for the generation of the two necessary voltage rails.