Digital control/modulation platform for a modular multilevel converter system

Modular Multilevel Converters (MMC) have proven to be suitable for high-power medium-/high-voltage energy conversion. They are based on the series connection of multiple submodules and have all the advantages of high modularity in the power stage. However, the control and proper generation of switching signals for all the power switches including the MMC capacitors voltage balance is not straightforward. This work presents a flexible digital control/modulation platform able to drive an MMC. The resulting digital platform enables future research of modulation and control schemes. A grid synchronization technique is included to improve modulation harmonic performance in a grid-tied MMC. Experimental results shows the practicability of the proposed platform.