A high voltage ratio and low stress DC-DC converter with reduced input current ripple for fuel cell source

A new single-switch non-isolated dc-dc converter with high-voltage gain and reduced semiconductor voltage stress is proposed in this paper. The proposed topology is derived from the conventional boost converter integrated with self-lift Sepic converter for providing high voltage gain without extreme switch duty-cycle. The reduced voltage stress across the power switch enables the use of a lower voltage and RDS-ON MOSFET switch, which will further reduce the conduction losses. Moreover, the low voltage stress across the diodes allows the use of Schottky rectifiers for alleviating the reverse-recovery current problem, leading to a further reduction in the switching and conduction losses. Furthermore, the "near-zero" ripple current can be achieved at the input side of the converter which will help improve the fuel cell stack life cycle. The principle of operation, and theoretical are performed. Experimental results of a 100 W/240 V-dc output with 24 Vdc input voltage are provided to evaluate the performance of the proposed scheme. (C) 2014 Elsevier Ltd. All rights reserved.