High-efficiency voltage-clamped DC-DC converter

This study investigates a newly designed DC-DC converter with reduced reverse-recovery current and switch voltage stress. A high-efficiency clamped-voltage DC-DC converter is designed by way of the combination of inductor and transformer to increase the voltage gain. Moreover, one additional inductor provides the reverse current path of the transformer to enhance the utility rate of magnetic core. In addition, the voltage-clamped technology is used to reduce the switch voltage stress so that it can select the Schottky diode in the output terminal for alleviating the reverse-recovery current and decreasing the switching and conduction losses. Furthermore, the closed-loop control methodology is utilized in the proposed scheme to overcome the voltage drift problem of the power source under the variation of loads. Thus, the proposed converter topology has favorable voltage-clamped effect and superior conversion efficiency. Some experimental results via an example of a proton exchange membrane fuel cell (PEMFC) power source with 250 watts nominal rating are given to demonstrate the effectiveness of the proposed power conversion strategy.