High-Efficiency Fuel Cell Power Conditioning System With Input Current Ripple Reduction

A high-efficiency fuel cell power conditioning system with input current ripple reduction is proposed. The proposed system consists of a high-efficiency high-step-up current-fed resonant push-pull converter and a full-bridge inverter. The converter conserves inherent advantages of a conventional current-fed push-pull converter such as low input-current stress and high voltage conversion ratio. Also, a voltage-doubler rectifier is employed in order to remove the reverse-recovery problem of the output rectifying diodes and provide much higher voltage conversion ratio. The current ripple reduction control without an external component is suggested. Therefore, the proposed system operates in a wide input-voltage range with a high efficiency. By using a current-ripple reduction control, the input current ripple is furthermore reduced. A 1.5-kW prototype is implemented with input-voltage range from 30 to 70 V. Experimental results show that minimum efficiency at full load is about 92.5% and that ripple current is less than 2% of the rated input current.