Hybrid DC–DC Converter With Novel Clamp Circuit in Wide Range of High Output Voltage

Abstract

In this paper, a hybrid converter with a novel clamp circuit is introduced. This hybrid converter integrates a phase-shifted full-bridge (PSFB) converter with a half-bridge (HB) LLC converter. On the primary side, the lagging leg of the PSFB converter is shared with the HB LLC converter. On the secondary side, the full-bridge rectifiers (FBR) of both converters are connected in series. Due to its series connection structure on the secondary side, this hybrid converter is suitable for high output voltage applications. The converter also includes the novel clamp circuit, which consists of two diodes and one capacitor connected to the center of the transformer. The proposed converter can overcome many drawbacks of conventional PSFB converter. Lastly, it offers improvements in efficiency, power density, and cost. To validate the viability of the proposed converter, a 3.3kW prototype was tested.

Keywords

• Circulating current
• clamp circuit
• electric vehicle (EV)
• fast charge
• phase-shifted full-bridge converter
• zero-voltage and zero-current switching (ZVZCS)