Reverse power flow study of an isolated Quasi-Switched-Capacitor DC/DC converter for automotive applications

This paper presents the study of the reverse power flow of an isolated Quasi-Switched-Capacitor (QSC) DC/DC converter for automotive applications. The converter employs a QSC DC/AC front-stage circuit with a 3:1 voltage step-down ratio, and a synchronous-rectifying-current-doubler post-stage circuit. The reverse power flow is delivered from the 14 V dc bus to the high voltage (HV) dc bus, for the vehicle starting up operation. To implement the reverse power flow, the control method is described, and the converter operation principles are analyzed. The simulation and experiment results of a 1 kW prototype based on silicon carbide (SiC) MOSFETs on the HV side are provided.