本論文主要研製一台100 W輸出的直流轉換器，二次側選用倍流整流的雙晶順向-返馳式轉換器。傳統順向式轉換器之缺點為功率開關所承受的電壓應力大於兩倍的輸入電壓，不適合高壓輸入。而本論文所使用之架構保留雙晶順向式轉換器之優點，功率開關之跨壓為一倍之輸入電壓，僅為傳統順向式轉換器所承受電壓應力的一半；並且，在返馳期間將儲存在鐵芯之磁能由二次側輸出至負載，所以有更小的電壓和電流漣波。
　　文中針對此架構進行電路分析，並提出設計流程，再使用Simplis模擬軟體完成包含切換晶體、變壓器圈數比(NP/NS)、激磁電感、輸出二極體與輸出電感在內之電路模擬，最後並實作一台100 W具倍流整流之雙晶順向-返馳式轉換器，利用實測結果驗證模擬和理論。

　　This thesis mainly studies and implements a 100 W DC/DC dual-switch forward-flyback converter with current doubler rectification. One disadvantage of the conventional forward is the voltage stress of switch which is usually more than two times input voltage, and it results in trouble when the input voltage is high. In this thesis, the structure of a conventional dual-switch forward converter is used to reduce the voltage stress of switch. It has the advantage that the voltage stress on each switch is the same value as the input voltage, a half of voltage stress of switch of the conventional forward converter. Besides, due to the property of flyback, the magnetic energy would be sent to the load during retrace interval, the ripples of voltage and current are smaller.
　　The circuit analysis of this topology is discussed. Then the circuit parameters such as the switch, the turns ratio (Np/Ns), magnetizing inductances of the transformer, the output diodes, and the output inductance are verified by using the SIMPLIS simulation tool. Finally, a 100 W dual-switch forward-flyback converter with current doubler rectification is implemented. Experiments are conducted to verify the simulation and theoretical analysis.

[1] Muhammad H. Rashid, “Power electronics: circuits, devices, and applications, Third Edition,” Prentice Hall, 2003.
[2] 梁適安，交換式電源供應器之理論與實務設計，全華科技圖書出版，民國98年8月。
[3] Abraham I. Pressman, “Switching Power Supply Design, Third Edition,” McGraw-Hill Companies Inc., 2009.
[4] N. Mohan, T. M. Undeland, W. P. Robbins, “Power electronics: Converter, Applications, and Design, Third Edition,” John Wiley&Sons, Inc., 2002.
[5] H. E. Tacca, “Single-switch two- output flyback-forward converter operation,” IEEE trans. on Power Electronics, Vol.13, No.5, Sept. 1998, pp. 903-911.
[6] Kusuhara Yoshito, Ninomiya Tamotsu and Nakagawa Shin, “Steady-State Analysis of a Novel Forward-Flyback-Mixed Converter,” Power Electronics and Motion Control Conference, 2006. EPE-PEMC 2006. 12th International , vol., no., pp.60-65, Aug. 30 2006-Sept. 1 2006.
[7] Kusuhara Yoshito, Ninomiya Tamotsu and Nakagawa Shin, “Complete analysis of steady-state and efficiency considerations in a Forward-Flyback Mixed Converter,” Power Electronics, 2007. ICPE '07. 7th Internatonal Conference on , vol., no., pp.620-624, 22-26 Oct. 2007.
[8] Himmelstoss F.A., Votzi H.L., “Comparison of a new combined four-diode forward-flyback converter with the classical forward converter,” Signals, Circuits and Systems, 2009. ISSCS 2009. International Symposium on , vol., no., pp.1-4, 9-10 July 2009.
[9] Huber L., Jovanovic M.H., “Forward-flyback converter with current-doubler rectifier: analysis, design, and evaluation results,” Power Electronics, IEEE Transactions on , vol.14, no.1, pp.184-192, Jan 1999.
[10] Yingdong Wei, Xiehua Wu, Yilei Gu and Hao Ma, “Wide Range Dual Switch Forward-Flyback Converter with Symmetrical RCD Clamp,” Power Electronics Specialists Conference, 2005. PESC '05. IEEE 36th , vol., no., pp.420-424, 16-16 June 2005.
[11] Bor-Ren Lin, Jin-Fa Wan, Chien-Lan Huang and Huann-Keng Chiang, “Analysis of the Two-Switch Forward Converter with Synchronous Current Doubler Rectifier,” Industrial Electronics and Applications, 2007. ICIEA 2007. 2nd IEEE Conference on , vol., no., pp.2299-2304, 23-25 May 2007.
[12] Hong Mao, Songquan Deng, Abdel-Rahman Osama, Wang T.C.Y. and Batarseh I., “A modified current-doubler rectifier for DC-DC converters to achieve balanced average currents,” Power Electronics and Motion Control Conference, 2004. IPEMC 2004. The 4th International , vol.2, no., pp.610-614 Vol.2, 14-16 Aug. 2004.
[13] Lin B. R., Wan J. F. and Hsieh F. Y., “Analysis and Implementation of an Active Clamp Two-Switch Converter with Current Doubler Rectifie,” Industrial Electronics Society, 2007. IECON 2007. 33rd Annual Conference of the IEEE , vol., no., pp.1426-1431, 5-8 Nov. 2007.
[14] 謝沐田，低頻變壓器設計，全華科技圖書出版，民國97年10月。
[15] 何此昂，周渡海，變壓器與電感器設計方法及應用實例，人民
郵電出版社，民國100年2月。
[16] Application Handbook, “TDK FERRITE CORES for Power Supply and EMI/RFI Filter,” TDK Corporation, July, 1990.
[17] Application Handbook, “MAGNETIC POWER CORES,” Chang Sing Corparation, 2006.