DC Converter with Wide Soft Switching Operation, Wide Input Voltage and Low Current Ripple

A soft switching current-source resonant converter is presented and implemented for wide voltage applications such as fuel cells and solar power. AnLLC(inductor-inductor-capacitor) converter is adopted to accomplish zero voltage (current) operation on active switches (diodes). Thus, the circuit efficiency is increased. The interleaved pulse-width modulation (PWM) converter is employed on the input side to accomplish low input ripple current. A hybridLLCconverter is adopted to achieve wide voltage operation fromV(in, min)to 4V(in, min)and to improve the weakness of a conventionalLLCconverter. Half-bridge diode rectification is employed on the output side to decrease power loss on the rectifier diode. To confirm the theoretical analysis and feasibility, experimental verifications with a 500-W prototype are demonstrated in this paper.