LCL-resonant single-switch isolated DC-DC converter

Abstract

Isolated converters are desirable in DC-DC power conversion applications where an isolation and/or a large voltage step-up gain is needed. The existing isolated DC-DC converters either utilise many switches to achieve high efficiency or use few switches which result in low efficiency. This study proposes a new single switch, isolated DC-DC converter with an LCL-resonant circuit. The proposed isolated DC-DC converter has the advantages of not only using the least number of switches (i.e. one switch), but also achieving zero-current switching when the switch is turned off. Experimental results are provided to validate the theoretical analysis of the proposed converter. Results show that the proposed converter has lower voltage stress and higher efficiency than the corresponding hard-switched converter.