Research On A Single-Satge Boost-Flyback PFC Converter

In order to reducing harmonic pollution in grid, Power Factor Correction (PFC) must be used to make the input current harmonic of power supplies accord with harmonic standards, such as IEC 1000-3-2. Recently, the significance of PFC technology has been realized, and research on PFC becomes very important in power electronics technology.In low to medium power level, single-stage PFC converters are more preferred due to their simple circuit topology, easy control, low cost and so on. A novel single-stage PFC converter was studied deeply in this paper.Firstly, the paper proposed a novel single-stage Boost-Flyback PFC converter, which is derived by combining a Boost circuit and a dual coupled windings flyback. Two bulk capacitors are used to store power energy from input source, and then feed on primary winding of the flyback transformer.In addition, the capacitors can absorb the leakage inductances energy and clamp voltage of power switch. Secondly, by adding parallel power transfer concept and line voltage feedback winding, parallel single-stage Boost-Flyback PFC converter and line voltage negative feedback single-stage Boost-Flyback PFC converter were proposed respectively. Basic principle, steady-state performance, design consideration and devices choosing of the converters were discussed in this paper. A simple voltage compensation method was proposed for these single-stage PFC converters, which can improve power factor (PF) and reduce total harmonic distortion (THD).Finally, experimental results of the 150W/24V prototypes were studied and compared, and theory analysis was experimentally verified.