A Three-Phase Modular Isolated Matrix Converter

This paper discusses the analysis, design, and experimental validation of a modular isolated matrix converter (MIMC), including modulation, commutation, and control. The MIMC topology is a single-stage high power density ac-ac converter, which is attractive for traction applications and space-restricted low voltage (LV) or medium voltage (MV) future distribution networks. The topology under study utilizes bidirectional switches based dual-active-bridge cells as basic building blocks. A single cell would have limited practical application as the output frequency is locked to the input one. On the contrary, the repetition of single cells proposed in the MIMC extending the matrix converter concept, achieves variable frequency operation while also providing a modular structure. However, the presence of medium frequency transformers in each cell poses additional challenges for modulation and safe commutation that are discussed and solved in this paper. Experimental results from a proof-of-concept 6 kW laboratory scale prototype validate the practical feasibility and the operation of the MIMC.