Novel Isolated Multilevel DC–DC Power Converter

Abstract

An isolated multilevel dc-dc power converter is proposed in this paper. The proposed isolated multilevel dc-dc power converter consists of an isolated power converter, a series/parallel switching circuit, and an output L-C filter. The isolated power converter is composed of a half-bridge inverter, a three-winding transformer, and two full-bridge rectifiers. The half-bridge inverter is switched in constant duty to generate two output dc voltages through two secondary windings of the three-winding transformer and two full-bridge rectifiers, respectively. The series/parallel switching circuit is used to control the two output dc voltages of the isolated power converter connected in series or in parallel, to control the output voltage of isolated multilevel dc-dc power converter. To verify the performance of the proposed isolated multilevel dc-dc power converter, a prototype is developed and tested. The experimental results show that the proposed isolated multilevel dc-dc power converter has the expected performance.