| 摘要 |
A single-stage power factor correction power supply has two transformers: a main transformer and an auxiliary transformer (forward transformer). The main transformer transfers energy form the primary circuit to the secondary circuit. The auxiliary transformer is used to correct input current waveform. An extra winding of the auxiliary transformer is used to reduce the voltage stress of the switch component. The advantage of this design over the two-stage power supply is that the voltage across the storage capacitor can be designed to be only slightly higher than the peak value of the rectified input voltage. Therefore, it uses less energy to correct input current waveform and results in less of an Electromagnetic Compatibility (EMC) problem because it has a lower input current amplitude through the inductor than that of the two-stage PFC power supply. It increases power supply unit reliabilty and efficiency. -BD1 0 T103 4I T 0' T1 2 r- -4 2P T 02 1101 ocodry Cl4 Fig.3 T12 k' + C1t Fig. 3 Fly-Back converter secondary circuit configuration Fig.4 Forward converter secondary circuit configuation |
