Study on soft-switching and output capacitor reduction techniques for high performance PFC stage in power supply

Abstract

Power supplies, which are essential components for supplying the power to the electronic devices, increasingly higher efficiency and smaller volume of the power supplies are required to solve the environmental problems and limited space. Accordingly, many researches have been conducted for the high efficiency and high power density of the power supplies. Meanwhile, a power supply of 75W or higher is composed of a power factor correction (PFC) stage and a DC/DC stage to supply the power to the electronic devices. In this dissertation, in order to solve the hard switching problem that causes an efficiency degradation of the PFC stage, a new structure and control technique is proposed. In addition, a new technique which can reduce the volume of the output capacitor in PFC stage is proposed. Therefore, the power supply can achieve the high efficiency and high power density than the conventional research. The performance of the proposed research are verified with the server power supply which is being developed a lot due to the rapidly increasing data traffics and power consumption of the data center. Moreover, the proposed research can be easily applied to the various applications as well as the server power supply.