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

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.