Estudo da aplicação de transformadores intercelulares em inversores de tensão

• Ano de defesa: 2014
• Autor(a) principal: Sergio Alejandro Diaz Contreras
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Engenharia Elétrica; Engenharia elétrica
• Link de acesso: http://hdl.handle.net/1843/BUOS-9QUHYQ

Interleaved inverters are a paralleling strategy that allows the construction of high power inverters by using components with lower power rating; it also reduces the harmonic distortion of the output voltage and improves the dynamic behavior of the inverter. Additionally, when the parallel connections are made by means of magnetically coupled inductors (or by using transformers), it is possible to obtain a gain in terms of volume reduction. Furthermore, when the parallel connection of the inverters is made by means of magnetic components built with high permeability cores, current distribution in the inverter is naturally improved. However, due to the differences that may exist among paralleled modules, a well balanced distribution can not be ensured and also a low frequency AC component may circulate through the paralleled inverters; this could lead the inverter to an undesirable behavior (overheating of some components and/or the saturation of the ferromagnetic core). In the other hand, some difficulties may arise by coupling the paralleled inverters, such as the fact that the design of the magnetic components and the control of the inverters currents are normally difficult. In this way, in order to obtain strategies and procedures that allow the application of interleaved inverters with magnetically coupled legs in high power applications, both issues are studied in this work. The first part of this work shows a strategy to design the magnetic components used for the parallel connections. In the second part, a modeling strategy and two different control techniques are presented. Furthermore, the theoretic procedures shown in this work are verified by means of the implementation of a four-leg interleaved inverter with an output voltage of 127V/60Hz. As a contribution to the current state of the art of the interleaved inverters with magnetic coupling, this work presents some analytical procedures that allow a better understanding of the inverter behavior. Furthermore, due the lack of information currently available that is focused in the control design problem for these inverters, the modeling and control strategy developed here represent an initial contribution to the study of the interleaved inverters.