Avanços em conversores fonte de corrente.

Abstract

This work aims to study the current source converters being divided in two parts: Part I - Hbridge single-phase current source converters; and Part II - X-type current source converters. The main objective of this work is to develop new topologies that can increase the current source converter competitiveness. The research is guided towards the development of new power electronics solutions that can increase the efficiency and/or power density without compromising the power quality or the operation of the converter. Part I studies H-bridge single-phase converters solutions with reduced active switch count (asymmetric topologies). Besides the conventional single-phase topology, three-level and multilevel topologies are studied. Besides the achievement of the proposed objectives in Part I, the low power density of single-phase converters motivated the study of the multiphase version of the topologies studied in Part I. Part II regards multiphase solutions, aiming the reduction of active switch count and power losses. As done in Part I, the presentation of the new topologies is structured by inherent characteristics of the conventional multiphase current source converters. The two-phase X-type current source converter is reviewed, being followed by the proposal of its generalized solution (multiphase), after that,the assymetrical technique presented on Part I is applied to the X-type current source converters, resulting in the asymmetrical X-type topologies. Also a synchronization technique for single-phase ACDC- AC converters is presented, aiming to reduce the DC-link current oscillation. The presented topologies are validated via simulation and/or experimental results, showing their feasibility and improvements when compared to the conventional converters.