Development of buck PFC AC-DC converter using an active buffer

Abstract

This paper discusses a new circuit configuration and a control method for a single-phase AC-DC converter with power factor correction (PFC). The proposed converter can achieve low total harmonic distortion (THD) for the input current, and at the same time, it can use an active buffer to control the low output DC voltage ripple. The proposed converter does not require large smoothing capacitors and large inductors, which are conventionally required in such converters to decouple the power ripple with a frequency twice that of the power supply. The buffering energy ismaintained by a small capacitor, which controls the voltage variation in the capacitor using the active buffer. In this paper, the fundamental operations of the proposed converter are confirmed by experimental results. From the experimental results, it is found that the input current THD is 1.44%, the ratio of the output voltage ripple is 6.33% and the input power factor (PF) is greater than 99%. In addition, a maximum efficiency greater than 96% is obtained in the prototype. © 2013 The Institute of Electrical Engineers of Japan.