Since the AC-DC conversion is widely spread in power sources, this work proposes a novel strategy of multi-pu[se topologies, associated to the ha[f-controlled boost-based rectifier, which has the follows main advantages: [ow Total Harmonic Distortion of the line current (THDi), below 2%; Power Factor (PF) close to unit; simple gate drive circuit, since all active switches are connected to the same reference; robustness given that the DCM operation results the peaks of the current naturally follow the voltage waveform. The control circuit becomes very simplified because all the switches are synchronized and only one basic voltage loop should be used to regulate the DC output, without current sensors. In addition, the commutation process occurs after the current in the diode becomes zero (DCM), without losses and current stresses due to the diode reverse recovery. The simulation analysis shows a significant improvement of PF once the THDi is lower than 2% while the conventional 12-pu[se topologies have about 14%. Each conventional three-phase bridge rectifier is replaced by a three-phase ha[f-controlled boost based topology, also called of bridge[ess rectifiers. A 2.5 kW prototype is being built and its feature is a strong candidate for More Electric Aircraft (MEA) and Adjustab[e Speed Drive (ASD) applications.

A detailed analysis and validation of the DC-DC boost converter based on the three-state switching cell (3SSC) type-A are presented in this paper. The study of this topology is justified by the small amount of research that employs 3SSC-A and the advantages inherent to 3SSC-based converters, such as the division of current stresses between the semiconductors, the distribution of thermal losses, and the high-density power. Therefore, a complete static analysis of the converter is described, as well as the study of all voltage and current stresses in the semiconductors, the development of a loss model in all components, and a comparison with other step-up structures. Additionally, the small-signal model validation is accomplished by comparing the theoretical frequency response and the simulated AC sweep analysis. Finally, implementing a simple controller structure, the converter is experimentally validated through a 600 W prototype, where its overall efficiency is examined for various load conditions, reaching 96.8% at nominal load.

This paper proposes two non-isolated step-down DC–DC converters based on the type-A three-state switching cell (3SSC-A), resulting in an alternative to the buck and buck-boost classical converters, respectively. The proposed topologies are part of a group of unexplored converters that employ the 3SSC-A, which has the advantages of 3SSC-based converters, such as high power density, reduced current stress on the semiconductors and suitable thermal loss distribution. In this regard, a complete static analysis is performed, including a detailed study of all semiconductor voltage and current efforts and developing loss models for each one. Moreover, by using simulation models, AC sweep analyses validate the dynamic frequency response of each converter’s small-signal models, and PI-based output–voltage closed-loop controllers are duly designed. Finally, the topologies are experimentally validated through the implementation of adequately designed prototypes, achieving efficiency values greater than 91% under several output power rates varying from 50% to 100%.

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