A multi-carrier PWM for AC-DC-AC converter without DC link electrolytic capacitor

This study proposes a multi-carrier pulse width modulation (PWM) for AC-DC-AC converter without DC link electrolytic capacitor. The AC-DC-AC converter consists of an AC-DC active front-end converter, a DC-AC voltage source inverter, and a 10 uF ceramic capacitor in dc link. The DC bus voltage controller with load compensator is utilized to maintain the voltage of the DC link capacitor at designed value. Furthermore, the multi-carrier PWM is utilized to reduce the common-mode voltage (CMV) of AC-DC active front-end converter and DC-AC inverter. The simulation and test results are presented to validate the performances of the proposed scheme.