Conversores CA-CC multiníveis do tipo boost com elevado fator de potência e operação em condução descontínua: estudo de topologias monofásicas, trifásicas, não isolados e isoladas

Abstract

This work presents the study and development of new topologies based on interleaved boost operating in discontinuous conduction mode. Firstly, are proposed two new rectifiers, one single-phase and another three-phase, where the main differential is the three-level configuration, reducing the voltage stress across the semiconductors. Other characteristics are the low input current ripple and high-power factor without current control loop due to the discontinuous conduction mode, where the input current follows the input voltage. These rectifiers are an interesting solution for low power applications with low cost and simple implementation. The proposed rectifiers can be integrated with multilevel cells as Neutral Point Clamped (NPC), flying capacitor and series connections of converters. In literature review several works present the integration of interleaved boost with NPC cell only, thus twelve new integrated topologies are proposed in the paper based on the integration of proposed rectifiers with flying capacitor, series connection of half-bridge, series connection of full-bridge and series connection of forward converters. For the fullbridge and forward converters a double input rectifier can be used, dividing the current levels. In the paper the analysis of non-isolated converters is presented. The operation is verified by simulation and a laboratory prototype. For the integrated converters, based on half-bridge and full-bridge series connection are discussed, and experimental results are presented. The proposed converters can operate with three different modulations: classical multi-phase PWM, asymmetrical PWM and frequency modulation. For asymmetrical modulation the voltage in output capacitors are unbalanced, thus are proposed two techniques to solve this problem.