近年来，电源技术无论在理论研究，还是生产应用方面都取得了许多成果和长足的进步。开关电源的研究涉及电力电子、自动控制等技术领域，软开关、高效率是开关电源的重要研究方向。因此，PFC技术和软开关PWM技术作为成熟的技术，近些年来在中、小功率乃至大功率开关电源中得到普遍的应用。 本文研究设计了一种具有功率因数校正和软开关技术的高效率开关电源。该开关电源主要分为两个部分，前一部分为单相有源功率因数校正电路，后一部分为采用移相控制软开关技术的全桥变换器。 论文首先介绍了开关电源技术的发展以及涉及到的技术领域，然后阐述了现阶段几种提高开关电源技术的新方法，最后详细叙述了整个系统的设计。在详细分析和研究单相有源功率因数校正原理的基础上，设计出有源功率因数校正电路，并给出电路中升压电感的设计方法。同时，设计出了大功率移相控制全桥软开关PWM DC/DC变换器，详细的研究了实现ZVS的条件。最后研制出了实验样机，并给出了实验样机的功率因数校正电路和移相全桥软开关变换电路的实验波形。

In recent years, power supply technique has developed very quickly and it has obtain very big of progress in theories researching and produced application. The research of power supply technique involves many realms such as the electric power electronics and the auto control. The soft switch technique and the high efficiency are important research contents of power supply. Therefore, Power Factor Correction (PFC) technique and soft-switching PWM technique are both widely applied in low power SMPS and high power SMPS. A high performance SMPS with PFC and soft-switching techniques is designed in this paper. It consists of two stages. The first one is single-phase power factor correction circuit. The second one is a full-bridge converter using phase-shifting control soft-switching technique. First of all, the paper introduced the development of switch power supply and it involved technology field, subsequently narrated many methods of advance of switching power supply. And then the paper introduced the design course of the whole system. Based on the detailed analysis of the principle of single-phase active PFC, the high power active PFC circuit is designed, and the method of designing boost inductor is also given in the paper. A high power phase-shifted-control soft-switching full-bridge converter is designed, and the condition of achieving ZVS is studied in detail. Finally, the waves of a prototype are given.