Common-mode voltage injection control method and apparatus for inverter

A common-mode voltage injection control apparatus, wherein the common-mode voltage injection control apparatus is applied to a three-phase three-level inverter and comprises a memory and a processor, the memory stores a computer program, and according to the computer program, the processor performs the following operations:

• obtaining a direct current bus voltage and three-phase port voltages of the three-phase three-level inverter;
• calculating a common-mode voltage for a discontinuous pulse-width modulation DPWM mode based on the three-phase port voltages and an output power command;
• calculating a common-mode voltage for a model predictive control MPC modulation mode based on the direct current bus voltage, the three-phase port voltages, and the output power command;
• determining a modulation proportion based on a maximum phase voltage peak value of the three-phase port voltages, the direct current bus voltage, and a power factor of the output power command;
• and
• generating a common-mode injection voltage based on the common-mode voltage for the DPWM mode, the modulation proportion, and the common-mode voltage for the MPC modulation mode, wherein
• the common-mode injection voltage is used to generate an output voltage modulation wave of the three-phase three-level inverter, the common-mode injection voltage comprises a first part and a second part, the first part of the common-mode injection voltage is the common-mode voltage for the DPWM mode, the second part of the common-mode injection voltage is the common-mode voltage for the MPC modulation mode, and a proportion of the first part of the common-mode injection voltage to the second part of the common-mode injection voltage is determined according to the modulation proportion.