Conversores CA-CC Isolados Bidirecionais com Estágio Integrado para Aplicações em Transformadores de Estado Sólido

Abstract

In recent years, the topological technology of Solid State Transformers (SST) has advanced greatly due to the great effort of researchers in the academic and industrial area. In view of this situation, this work presents a study of bidirectional isolated CA-CC converters with integrated stage for TES application. The proposed topologies are based on the three-level Dual Active Bridge (DAB) and three-level Neutral Point Clamped (NPC) converters and on the use of the Three State Switching Cells (3SSC). A study of the implementable topologies in SST is carried out through a bibliographical review of the main recently published structures. In the topological terms of the converter, the operating principle is presented, the vector map derived from the analysis of the space vectors of the switching states, the autotransformer analysis of the TSSC and the transformer isolating the DAB characteristic of the structure. Next, we show the modulation strategies adopted for the work, as well as the mathematical modeling of the power circuit and the control strategies implemented. Switching analysis of power switches is developed in order to obtain the Zero Voltage Switching (ZVS) and Zero Current Switching (ZCS) switching regions. In this work, the study of the electrical losses of the topology, both conduction and switching losses, is discussed. Finally, the proposed structure is compared with others present in the power electronics literature. The results of numerical simulations are developed in order to prove the theoretical analysis. A single phase prototype was implemented to collect experimental results, validating the theoretical study.