Electric vehicles (EVs) powered by batteries and other energy storage devices (ESDs), e.g., ultracapacitors, are expected to play an important role in the development of a more sustainable future. In this context, charging stations (CSs) are supposed to become the main sources of energy for charging the batteries, being strongly dependent on power electronic converters. This paper analyzes a bidirectional single-phase, three-level stacked neutral-point-clamped (3L-SNPC) converter for CS applications, which may behave as a rectifier or an inverter depending on the power flow direction. Besides, the derived analysis can be easily extended to the development of a three-phase version. Considering that the CS is capable of integrating the utility grid and renewable energy sources, it is possible to absorb or inject energy into the ac grid with high power factor and reduced harmonic content of the current. The main advantages of the bidirectional topology are the existence of a three-level voltage waveform across each leg and the neutral point, while filtering requirements are reduced when compared with typical two-level structures used in EV CSs; the voltage stresses on all semiconductors are equal to half of the total dc-link voltage; power factor is nearly unity in any operation mode; and the voltages across the dc-link capacitors are balanced. The thorough design of the power and control stages is presented, as well as experimental results from a laboratory prototype are discussed in detail.INDEX TERMS Bidirectional converters, charging stations, electric vehicles, resonant controller.

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Resumo -Este artigo propõe uma estratégia de controle preditivo baseado em modelo aplicado a um conversor boost com célula de comutação de três estados que confere mais simplicidade e sistematização nas fases de projeto e análise do controlador, cujo ganho integral ajustável dispensa o reprojeto nas matrizes de ponderação. Para simplificar a análise de estabilidade do controlador, utiliza-se o conceito de elipsoides de estabilidade, um assunto ainda pouco explorado neste contexto. O controle preditivo proposto parte da modelagem da planta no espaço de estados médio linear e variante no tempo, cujas variações paramétricas são tratadas como incertezas politópicas expressas por meio de desigualdades matriciais lineares (LMIs) com relaxações.Aspectos teórico-experimentais são aplicados e analisados em um conversor de 1 kW com incertezas na tensão de entrada e na carga. Além disso, para estabelecer uma base de desempenho, o MPC proposto é comparado com o controlador LQR clássico conhecido na literatura. A estratégia de controle proposta apresenta vantagens considerando as variações do modelo decorrente dos testes de cargas em aplicações de conversores estáticos CC-CC. Palavras-chave -Conversor ROBUST MPC-LMI CONTROLLER APPLIED TO THREE STATE SWITCHING CELL BOOST CONVERTERAbstract -This paper proposes a Model Predictive Control (MPC) strategy applied to Three State Switching Cell boost converter which leads more simplicity to the design steps and analysis to the controller, whose adjustable integral gain does not need the redesign of weighting matrices. To simplify the controller analysis, the ellipsoid stability concepts are used, a field few explored in this context. The proposed MPC starts from of Linear Time Varying(LTV) state space plant modeling whose parametric variables are modeled as politopic uncertainties via linear matrix inequalities (LMIs) approach with relaxations.Theoretical and experimental aspects are applied to 1 kW boost converter with voltage input and load uncertainties. Morevover, to lead the performance testing, the proposed MPC is compared with the classical LQR known in the literature.The proposed control strategy presents advantages considering the model variations due to load testing in DC-DC converters applications. Keywords -

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