| Summary: | 碩士 === 國立宜蘭大學 === 電機工程學系碩士班 === 104 === This thesis develops a high efficiency isolated power factor correction AC/DC converter, improving the conventional two-stage circuit topology to single-stage circuit topology. Proposed converter combines a front-end AC to DC Power Factor Correction (PFC) converter and back-end DC to DC Full-Bridge Phase Shift converter, then improving this two-stage circuit topology to a single-stage circuit topology. To reduce costs front-end PFC converter and back-end DC to DC converter shares one arm switches and transform AC voltage to a stable low DC voltage. The proposed converter using an auxiliary circuit provided front-end switches operated at zero-voltage-switching turn on and auxiliary switches are operated at zero-current-switching turn off. By using phase shift technology all main switches in the back-end DC to DC converter can operated at zero-voltage-switching turn on. By making all elements operate in soft-switching situation, proposed converter can reduce switching-loss and increase efficiency. To get low current distortion and high power factor, input current using Continuous-Conduction-Mode (CCM), achieve voltage rising and give back-end phase shift converter a stable input voltage. A design example of 1000W converter is simulated and access realized to prove the theory and analysis.
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