An auxiliary winding with an associated capacitor is added on the
single-stage power factor corrector (PFC) based on fly-back conversion to
reduce the ripple on the dc output voltage. The associated capacitor takes
out partial energy at every switching cycle from the fly-back conversion
and releases the stored energy to the load at the valley of the rectified line
voltage. The negative effect of such an approach is that the converter does
not draw a current from the AC line at the lower voltage near zero
crossing, leading to deterioration in the power factor.
This thesis analyzes how an auxiliary winding affects the voltage of
the associated capacitor, which in turn changes the cut-in angle of the
input current and thus the power factor of the AC source. To facilitate the
implementation, the fly-back converter is operated at the boundary
conduction mode (BCM). A design example is given for the 24 V, 48 W
load, based on the derived equations. The laboratory circuit is built and
tested to verify the computer simulations and analytical predictions. The
experimental results confirm the circuit analyses on the converter
performances.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0721109-103203 |
| Date | 21 July 2009 |
| Creators | Hsiao, Li-yang |
| Contributors | Chih-Chiang Hua, Ching-Tsai Pan, Chin-Sien Moo, Ching-Ran Lee, Hong-Chan Chang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0721109-103203 |
| Rights | unrestricted, Copyright information available at source archive |
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