Revista Eletrônica de Potência (Brazilian Journal of Power Electronics)

Palavras Chaves: Conversor ca-cc isolado, Conversor Multinível Modular, modulação vetorial, Transformador de Estado Sólido

Resumo

Este artigo tem como objetivo apresentar o estudo teórico e a obtenção de resultados experimentais de uma topologia monofásica baseada em um conversor multinível modular entrelaçado. A estrutura pode ser empregada como o estágio ca-cc em aplicações de transformador de estado sólido. O objetivo é a conexão entre uma rede elétrica ca de média tensão e uma rede cc de baixa tensão. A nova técnica de entrelaçamento divide as correntes através das pernas do conversor multinível modular e é responsável pela modulação de tensão nos submódulos. O transformador de média frequência de 10 kHz fornece isolação galvânica e conecta o conversor multinível modular entrelaçado a um conversor de ponte completa. As características do conversor são discutidas, considerando a estrutura, o princípio de operação, a técnica de modulação e o esquema de controle. O sistema de controle regula a corrente de entrada e a tensão de barramento, no lado de alta tensão, e a tensão de saída e o fluxo de potência bidirecional, no lado de baixa tensão. A validação experimental do conversor é feita com um protótipo de pequena escala.

Title: Study and experimental validation of a single-phase AC-DC interleaved modular multilevel converter for solid-state transformers applications

Keywords: AC-DC power converters, Modular Multilevel Converter, Solid State Transformer, space vector modulation

Abstract

This paper aims to present the theoretical study and the obtaining of experimental results of a single-phase topology based on an interleaved modular multilevel converter. The structure can be employed as the ac-dc stage in solid-state transformer applications. The goal is the connection between a medium voltage ac grid and a low voltage dc grid. The new interleaving technique divides the currents through the legs of the modular multilevel converter and is responsible for the modulation of the voltage across in the submodules. The 10 kHz medium-frequency transformer provides galvanic isolation and connects the interleaved modular multilevel converter to a full bridge converter. The characteristics of the converter are discussed, considering the structure, the principle of operation, the modulation technique, and the control scheme. The control system regulates the input current and the bus voltage, on the high voltage side, and the output voltage and bidirectional power flow, on the low voltage side. The experimental validation of the converter is made with a scaled-down prototype.

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