Single-Stage APFC Converter With Additional Winding

With only one set of control system,single-stage PFC converter can realize the input current shaping and the fast regulation of output voltage. It especially fits low-power occasion well because of the advantage of simple structure and low cost. However, the energy-storage capacitors voltage is uncontrollable, varying with the input voltage and load. So how to reduce the voltage of energy- storage capacitor is the main problem of single-stage PFC converter.On this basis, the present research of active Power Factor Correction technology is introduced firstly. And then various topologies of single-stage PFC converter are compared. The universal model of Boost single-stage PFC converter is concluded in the end.Based on the above work, a new topology of single-stage PFC converter is presented in this paper. The operation principle of the circuit is analyzed in detail. Starting with the steady-state analysis, this paper presents the large-signal model of the circuit, designs the main parameters of the circuit, deduces the relation between inductance and energy-storage capacitor voltage, and presents the simulation and experimentation waveform of the circuit. The theoretical analysis and experiment indicate that the energy-storage capacitor voltage can be effectively reduced in this converter.On the basis of the new single-stage PFC converter, an additional transformer winding is added, forming the bus voltage feedback to further reduce the voltage across the energy-storage capacitor, but it will reduce the power factor. The turns of the transformer additional winding should be determined from the trade-off between lower voltage across the energy-storage capacitor and lower total harmonic distortion of input current. The paper presents the theoretical analysis of input current distortion,deducing the relation between inductance and energy-storage capacitor voltage and designing themain circuit and close loop parameters. Simulation and experimental results prove the validity of design.Finally, the paper concludes the research findings, and points out some future research areas,such as soft switch technique etc.