Hybrid Half- and Full-Bridge Converter with High Efficiency and Full Soft-Switching Range

A novel soft-switching converter combining resonant half-bridge and phase shifted full-bridge configuration is proposed to ensure the switches in the leading-leg operating at zero-voltage switching from true zero to full load, and the switches in the lagging-leg at zero-current switching with minimum duty cycle loss and circulating conduction loss by significantly reducing leakage or series inductance. A 3.4 kW hardware prototype has been designed, fabricated and tested to verify the validity and performance of the proposed circuit. Experimental results show that the proposed topology achieves 98% maximum efficiency, compact the output inductor size and soft-switching over a wide output voltage and current range and is attractive for electrical vehicle battery charger applications.