Multilevel conversion circuit having flying capacitor

A multilevel conversion circuit having a flying capacitor, comprising:

• a first bridge arm comprising a plurality of switches connected in series;
• a second bridge arm comprising a plurality of switches connected in series and the flying capacitor, wherein a midpoint of the second bridge arm and a midpoint of the first bridge arm are connected to a first series branch, wherein the first series branch is defined by a first current limiting circuit, a power supply and an inductor;
• a DC bus capacitor connected in parallel to the first bridge arm and the second bridge arm;
• a rectifier circuit having an input end coupled to the power supply;
• a first auxiliary power supply having an input end coupled to an output end of the rectifier circuit;
• and
• a controller coupled to the first auxiliary power supply and the plurality of switches of the second bridge arm;
• wherein after the controller is activated, the controller is configured to control the corresponding switches of the second bridge arm to turn on, and the power supply charges the flying capacitor through the corresponding switches of the first bridge arm, the corresponding switches of the second bridge arm and the first current limiting circuit.