ZVS PWM Hybrid Full-Bridge Three-Level Converter

Server power is specially designed for computer systems which has a large market, so it has become a focus in the field of Power Electronics. For computer system, the evolution of digital logic technology continues to impose increasing supply current needs while demands its power has high efficiency and high power density at the same. All these prompts great challenges for the designers of power supply. Aimed at this problem, we proposed a Zero-Voltage Switching PWM Hybrid Full Bridge Three-level (ZVS PWM H-FB TL) converter in this thesis.In the thesis's first part, it analyzes the converter's operation principle and the duty cycle loss in details, makes a round comparison with the conventional full-bridge(FB) converter. Saturable inductance is introduced to eliminate the voltage swing and overshooting on the output rectifier diodes, then discusses its parameter design in detail; Find out the mechanism of the body diode's reverse recovery effect of the chopping switches, give outseveral relevant solutions and verified by experiments.In the thesis's second part, it proposes a ZVS H-FB TL Converter with Synchronous Rectifiers(SR) in order to improve efficiency. It analyzes the SR's control method and its operation principles, then bring forward a best control strategy witch is fit to this converter.