Topology and control of single power source hybrid asymmetrical multilevel converter

Single power-sourced hybrid asymmetrical converters have some merits such as simple structure, reduction in volume and cost compared with hybrid asymmetrical converter, but its control is too complex. A novel single power asymmetrical converter topology was proposed in the paper to solve the difficulty in control of the neutral-point voltage and sub-converter capacitor's voltage synchronously. The control of converter was much simplified through adding an assistant leg to control the neutral-point voltage independently. PI control was adopted to control the system stability of sub-converter capacitor's voltage and redundant states selection was used to control the sub-converter capacitor's voltage in every period of output voltage. Finally, detailed simulation and test results verify the proposed topology and control method.