HAIT Journal of Science and Engineering B Volume 2, Issues 3-4, pp. 305-326 © 2005 Holon Academic Institute of Technology | ||||
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High power factor forward AC-DC converter with low storage capacitor voltage stress
Dylan Dah-Chuan Lu
PowereLab Limited, 1/F Technology Innovation and
Incubation Building | The University of Hong Kong, Pokfulam Road, Hong Kong, China *e-mail: eiedclu@alumni.polyu.edu.hk Received 1 March 2005, accepted 9 August 2005
| Forward converters generally exhibit poor power factor when employing in the AC-DC conversion, due to the presence of zero input current near the zero crossing of line input voltage. In this paper, a single-switch forward converter with high power factor and low storage capacitor voltage stress is proposed. By adding a stack up voltage on top of the reflected input voltage on the forward converter secondary, the dead angle of input current is eliminated. The storage capacitor voltage is also kept smaller than the peak input voltage throughout entire line and load conditions. Power factor correction and fast output regulation are achieved simultaneously by using only a single switch and a single voltage-feedback control loop. Parameters that affect the storage capacitor voltage and input current are examined. Experimental results showed the effectiveness of the proposed converter.
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