A Hybrid Double Parallel Converter with Voltage Self-Balancing and Its Control Method

In order to realize the comprehensive optimization of the operating efficiency and cost of the converter, a hybrid dual parallel 5-level converter (HDP5C) is proposed in this paper. The HDP5C consists of a set of low-frequency arm based on Si IGBT and a set of high-frequency self-balancing arm based on SiC MOSFET, where the current stress of SiC MOSFET is only half of that of Si IGBT. Secondly, the topology and modulation strategy of HDP5C are introduced. Secondly, a specific hybrid modulation strategy is proposed for the HDP5C, in which SiC MOSFET operates at high frequency switching and Si IGBT operates at power frequency switching to optimize the operating loss of HDP5C. Finally, the effectiveness and feasibility of the proposed topology, control strategy and self-balancing capability are verified by simulation results.