Step‐up switched‐capacitor module for cascaded MLI topologies

Abstract

This study presents a new module for cascaded multilevel inverters (MLIs) based on switched-capacitor technique. Charging of the capacitors in the proposed switched-capacitor cell is performed in a self-balancing form. Voltage boosting capability and generating bipolar voltage levels without requiring an end-side H-bridge inverter are remarkable benefits of the proposed topology. Thereby, semiconductors with lower-voltage ratings are applied in its circuit. Comparison of the proposed inverter with traditional topologies and other recently introduced MLIs shows that the proposed topology reduces the number of circuit elements and also total blocking voltage by switches. Moreover, the proposed inverter configuration and its operating principle, capacitance, and power loss calculations, and also topology extension to achieve higher levels are investigated in depth. Finally, an experimental prototype is built to verify the theoretical analysis and feasibility of the proposed topology.