Single-phase four-quadrant five-level converter

In order to drive the high-voltage large capacity motor and deliver the power generated by the motor when breaking to the power grid, a single-phase four-quadrant five-level converter was proposed. The working scheme was discussed and the equivalent circuits were drawn. The model of the switches was built, and the relationship between the switch state and voltage was revealed. The relationship between the capacitor voltage and the modulation method was analyzed and the corresponding algorithm was found, which can output the desired voltage and maintain the capacitor voltage. An experimental system was built and the experimental results show that the proposed inverter works properly. Also, the proposed algorithm and control strategy are proved to be practical and available.