Space Vector Modulation for a 5-level Reduced Multilevel Converter with capacitor balancing

Multilevel converters have many advantages in power electronics. This paper presents a multilevel converter based on flying capacitors that allows to increase the number of output voltage levels reducing the numbers of semiconductors necessary in comparison with the standard multilevel converters. In particular, the proposed converter, Reduced Multilevel Converter (RMC), is an attractive choice as it can generate high quality output waveforms and reach high power levels. Nevertheless, the modulation stage cannot be guaranteed or achieved easily in the proposed multilevel converter, for this reason previous works use MPC to avoid the modulation stage in this converter. In this paper, a simple closed-loop scheme, based on Space Vector Modulation (SVM), is used to properly modulate the converter output voltage in order to keep the capacitor voltages at the desired values, this strategy is totally compatible with MPC strategy for current control. As the proposed modulation strategy regulates the capacitor voltages, fast linear controllers can be used for the current tracking, improving the dynamic behavior of the overall system.