Full Range Capacitor Voltage Balance PWM Strategy for Diode-Clamped Multilevel Inverter

This paper briefly reviews virtual space vector pulse width modulation (VSVPWM) for the diode-clamped multilevel inverter (DCMLI). Based on the universal modulation model of the DCMLI with N-level, a modulation strategy named as full range capacitor voltage balance PWM (FRCVBPWM) is proposed, which has similar capacitor voltage balance characteristics as VSVPWM. The characteristic of FRCVBPWM is that there are respectively zero, N − 1 and N − 2 switching actions for the three phases of the DCMLI. Therefore, the total switching actions are greatly decreased compared with VSVPWM. The switching loss comparison between FRCVBPWM and VSVPWM is conducted by comprehensive simulations. Finally, the feasibility and superiority of FRCVBPWM over VSVPWM is verified by experiments.