An improved current-fed ZVS isolated boost converter for fuel cell applications

This paper proposes a novel current-fed ZVS isolated boost converter suitable for fuel cell applications. Preserving the advantages of the current-fed converter which include smaller input current ripple, lower diode voltage rating and lower transformer turns ratio, the proposed converter does not require any clamping and start-up circuits unlike the conventional current-fed converters. The voltage ratings of the primary switches and secondary diodes of the proposed converter are significantly reduced. The proposed converter can achieve ZVS at a lighter load condition with less leakage inductance. These characteristics of the proposed converter lead to a high overall efficiency over wider load range. Experimental results on a 1 kW prototype are provided to validate the proposed concept.