A DC voltage notching scheme for zero voltage switching (ZVS) of PWM inverters

This paper presents a DC voltage notching scheme for zero voltage switching (ZVS) of PWM inverters. The proposed scheme permits programmed DC voltage notching, i.e. the DC voltage can be brought to zero on command to facilitate ZVS of the inverter switches. This is achieved without any over voltage excursion in the DC-link and with minimal additional components. The proposed approach utilizes a simple control strategy which facilitates the use of several well known high performance PWM schemes for inverter control. A detailed analysis of the circuit operation is presented and a design procedure is outlined for proper selection of the circuit components. The feasibility of the proposed scheme is experimentally verified on a laboratory prototype