Extended dual modulation curves voltage balancing strategy for cascaded H-bridge rectifier

Abstract

This article has proposed a control strategy for balancing the capacitors' voltage of cascaded H-bridge rectifier. The working principle of cascaded H-bridge rectifier has been described, as well as the balancing boundary condition of capacitors' voltage. Then, the dual modulation curves control strategy has been proposed for balancing the capacitors' voltage in dc side of the rectifier. Furthermore, the logic expression of dual modulation curves strategy has also been discussed to handle with multiple cascaded H-bridges situation. With the proposed control strategy, the capacitors' voltage can be balanced under the unbalanced load condition. The simulation and experiments are presents to verify the performance of the proposed control strategy.