High efficiency power supply unit for server power application

In this paper proposed highly efficiency PSU(Power Supply Unit) for server power supply. To minimize power conversion loss, PFC(Power Factor Collection) circuit was designed into Bridgeless PFC using two switching components with 2 SiC diodes, and synchronous rectifier switching method was applied. An isolated DC/DC converter used LLC SRC(Series Resonance Converter) to increase power efficiency and reduce the voltage and current ripple, furthermore, the diode on the secondary side used the MOSFETs for synchronous rectifying with low Rds(on) to minimize the loss. Lastly, buck-boost converter circuit was chosen to step down the bucked 12V into 5V and 3.3V, the voltages which almost server power used. And converter design and loss reduction method was proposed. The whole circuit was designed with 650[W], and simulated and tested to verify theories and efficiency.