Reduced Stacked Multicell converter with minimized stored energy of flying capacitors

In this paper a new configuration of flying capacitor based multicell converter with a fewer number of power electronic switches has been introduced. Using the proposed configuration of Stacked Multicell converter, the number of output voltage levels and the RMS are doubled and the output voltage frequency spectrum has been improved. Also, the number and rating of components and the converter losses are decreased in comparison with conventional flying capacitor based converters. Furthermore, proposing a matrix configuration in this converter, the total stored energy of flying capacitors can be minimized. This configuration is based on Stacked Multicell converter and achieved by removing the switches generating negative half cycle of output waveform, which decreases the number of high frequency switches to half, and adding only two low-frequency switches to a matrix based structure of Stacked Multicell converter. A modified Phase Shifted Pulse Width Modulation control scheme has been applied to the proposed topology in order to maintain the natural balancing capability of flying capacitors. The simulation results obtained from PSCAD/EMTDC software confirm the validation of this proposed configuration advantages and its control method.