本論文為具同步整流與主動式功因修正半橋式諧振電源供應器之研製,首先討論主動式功因修正器之動作原理,實現高功因,在交流轉直流方面提供半橋式諧振電源供應器作為穩定直流電源輸入。其次討論半橋式諧振電源供應器之動作原理,在切換過程達到零電壓切換,降低功率元件開關損失及切換應力,當定頻控制頻率跟隨諧振頻率,亦能在工作時效率保持著最佳狀態。接著討論同步整流的動作原理,在次級測使用MOSFET代替Schottky來做整流,可減少因輸出電流所造成的零件上功率損失。 最後,製作此電源供應器的架構在負載變動下實際量測及探討,其中電源供應器輸入電壓為 ,輸出電壓為 ,輸入電壓在 時,系統最高效率可達90.52%。
This thesis presents results of study and implementation of half bridge resonant power supply with active power factor correction. First, active power factor correction approach was discussed to rectify the wave form distortion of bridge current and realize high power factor and low current harmonic. Afterward, it gave a stable high quality dc voltage input for half bridge resonant power supply. Second, half bridge resonant power supply could achieve Zero Voltage Switching (ZVS) in the switching process to reduce power losses. When the fixed frequency control was used for tracking the resonant frequency, this process also helped keep the system operated at the optimal condition. Then, synchronous rectifier (SR) the MOSFET used to substitute for the Schottky that is to rectify in the secondary side. This method been to reduce power loses on the components of the secondary side of circuit. Finally, the realizations of power supply system was implemented, measured and analyzed under load variations. The power supply was operated under 90Vac~264Vac input voltage range and 24Vdc / 10A was measured as an output. The experimental results showed that an optimum efficiency of proposed system can reach up to 90.52% at the input voltage of 230Vac.