2013 International Conference on Electrical Machines and Systems (ICEMS)
DOI: 10.1109/icems.2013.6754438
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Recent advances in magnetic materials and power semiconductor devices have led to the development of compact and lightweight medium voltage inverter with medium frequency-link, which would be a possible solution to reducing the weight and size of grid-connected photovoltaic (PV) inverter systems. This paper presents the design and analysis of a multiple-input multiple-output medium frequency-link based medium voltage inverters for step-up transformer-less direct grid connection of PV arrays. The multiple-output medium frequency-links generates multiple isolated and balanced dc supplies for all of the H-bridge inverter cells of modular multilevel cascaded (MMC) inverter. To verify the feasibility of the proposed system, a scaled down 1 kV laboratory prototype test platform with 5-level MMC inverter is developed. The design and implementation of the prototyping, test platform, and the experimental results are analyzed and discussed.