Hybrid Resonant and PWM Converter With High Efficiency and Full Soft-Switching Range

A novel soft-switching converter combining resonant half-bridge and phase-shifted pulsewidth modulation (PWM) full-bridge configuration is proposed to ensure the switches in the leading-leg operating at zero-voltage switching from true zero-load to full-load, and the switches in the lagging leg working at zero-current switching with minimum duty cycle loss and circulating conduction loss by significantly reducing leakage or series inductance. Experimental results of a 3.4-kW hardware prototype show that the circuit achieves true full-range soft switching with 98% peak efficiency. The hybrid resonant and PWM converter is attractive for electrical vehicle battery charger application.