在切換式轉換器的電路中，由於半橋式轉換器變壓器的磁滯迴路可操作在第一與第三象限，所以能對磁性元件有充分的利用，因此半橋轉換器的輸出能量較大。本文將混合式之切換技術配合半橋電路應用於返馳式轉換器來提高轉換器零電壓切換之範圍。此外輸出二極體也具有零電流切換的優點，且能夠減少轉換器的責任週期損失。由實驗的數據驗證，結合了混合式切換技術的電路可提高其性能。最後並將提出的切換技術與傳統電路之間做比較，以突顯本技術的實用性。

As the magnetic hysteresis loop can transverse over both the first and the third quadrants, the transformer of a half-bridge converter is able to process higher energy.This thesis proposes a hybrid-switching technique for half-bridge circuit that can be applied to flyback converters in order to increase the range of zero-voltage-switching (ZVS). In addition, the output diode can be turned off at zero current and the duty loss is minimized. Experimental results highlight the enhanced performance of the hybrid-switching technique on this circuit. Finally, the comparison on performances of the proposed converter and the conventional converter are performed to show the practicality of the proposed technique.

[1] Robert W. Erickson and Dragan Maksimovic,“Fundamentals of Power Electronics,” Second Edition, Kluwer Academic Publishers, 1999.
[2] G. C. Chryssis著，梁適安譯，“高頻交換式電源供應器原理與 設計，”全華科技圖書股份有限公司，民國八十四年。
[3] T. Tolle and T. Duerbaum,“Modelling of ZVS Transitions in Asmmetricals Half-Bridge PWM Converter, ” IEEE PESC, 2001, pp. 308-313.
[4] D. H. Seeo, O. J. Lee, S. H. Lim, and J. S. Park,“Asymmetrical PWM Flyback Converter,” IEEE PESC, 2000, pp. 848-852.
[5] T. M. Chen and C. L. Chen,“Analysis and Design of Asymmetrical Half-Bridge Flyback Converter,” IEEE Proc. –Electr. Power Appl., Vol. 149, No. 6, November 2002, pp. 433-440.
[6] P. Imberston and N. Mohan,“Asymmetrical Duty Cycle Permits Zero Switching Loss in PWM Circuits with No Conduction Loss Penalty,” IEEE Trans. Industry Application, Vol. 29, No. 1, pp. 121-125, Jan/Feb.. 1993.
[7] S. Korotkov, V. Meleshin, R. Miftahutdinov, and S. Fradlin,“Soft-Switched Asymmetrical Half-Bridge DC/DC Converter: Steady-State Analysis. An Analysis of switching Processes, ” IEEE INTELEC, 1997, pp. 177-184
[8] R. Oruganti, P. C. Heng, J. T. K. Guan, and L. A. Choy, “Soft-Switched DC/DC Converter with PWM Control, ” IEEE Trans. Power Electronics, Vol. 13, No. 1, 102-114, pp. Jan. 1998.
[9] R. L.Steigerwald, “A Comparison of Half-Bridge Resonant Converter Topologies,” IEEE Trans. Power Electron., vol. 3,No. 2, pp. 174-182, Apr. 1988.
[10] 洪碩成，具同步整流之非對稱半橋返馳式轉換器研製，國立臺灣科技大學電子工程系研究所碩士論文，2011年。
[11] EPARC著，葉奕伶譯，“電力電子綜論，”全華科技圖書股份有限公司，民國一百年。
[12] K. AI. Haddad, A. Bellahnid, V. Rajagopala, Y. Cheron, and H. Foch, “Novel Control Strategy to Improve Dynamic Performance of a Series Resonant Converter,” in Ind. Applications Soc. Annual Meeting, Pittsburgh, PA, 1988, pp. 806-812.
[13] Y. Ohashi, Y. Kuwata, and K. Mizuguti, “A 100 kHz, 2.7k W Rectifier Using a Series-Resonant Converter by Passing Discharge Current,” in Telecommunications Energy Conf. Florence, 1989, pp. 16.5/1-16.5/7.
[14] S. Sooksatra and C. Q. Lee, “Current Driven Series Resonant Converter,” in Applied Power Electronics Conf. and Exposition, 1990, vol. 2, pp. 128-139.
[15] W. M. Moussa and J. E. Morris, “Steady State Analysis for an Off-Line Series Resonant Converter,” in Southern Tier Technical Conf., US, 1990, pp. 23-29.
[16] S. Sooksatra and C. Q. Lee, “Nom-Resonant Coupled Parallel Resonant Converter,” in Symposium on Circuits and Systems, Champaign, IL, pp. 781-784.
[17] I. Batarseh and C. Q. Lee, “High-Frequency High-Order Parallel Resonant Converter,” IEEE Trans. Ind. Electron., vol. 36, no. 4, pp. 1708-1716, Nov. 1989.
[18] C. Q. Lee and S. Sooksatra, “Current Programmed Control Nonresonant Coupled Parallel Resonant Converter,” in Power Electronics and Variable-Speed Drives Conf. London, 1990, pp. 142-147.
[19] S. Buso, G. Spiazzi, and F. Sichirollo, “Study of the Asymmetrical Half-Bridge Flyback Converter as an Effective Line Fed Solid State Lamp Driver, ” IEEE Trans.Ind Electron. vol. 28, no. 99, pp. 4657-4667, Mar.2014.
[20] H. S. Kim, J.H.Jung, J.W. Baek, and H. J. Kim,“Ananlysis and Design of a Multioutput Converter Using Asymmetrical PWM Half-Bridge Flyback Converter Employing a Parallel-Series Tranformer,” IEEE Trans.Ind Electron.,vol.60,no.8,pp.3115-3125,aug.2013.
[21] B. Gu, C. Y. Lin, B. F. Chen, J. Dominic, and J. S. (Jason) Lai, “Zero-Voltage-Switching PWM Resonant Full-Bridge Converter with Minimized Circulating Losses and Minimal Voltage Stresses of Bridge Rectifiers for Electric Vehicle Battery Chargers, “IEEE Trans. Ind. Electron., vol. 28, no. 10, pp. 4657-4667, Oct. 2013.
[22] R. Liu and C. Q. Lee, “The LLC-Type Series Resonant Converter-Variable Switching Frequency Control,” in Symposium on Circuits and Systems, Champaign, IL, pp. 509-512.
[23] K. H. Liu and F. C. Lee, “Zero-Voltage Switching Technique in DC/DC Converter,” IEEE Trans. Power Electron., vol. 5, no. 3, pp. 293-304, Jul. 1990.
[24] K. Yoshida, T. Ishii, and N. Nagagata, “Zero Voltage Switching Approach for Flyback Converter,” in Telecommunications Energy Conf., Washington, DC, 1992, pp. 324-329.
[25] F. C. Lee, “High-Frequency Quasi-Resonant and Multi-Resonant Converter Technologies,” in Ind. Electronics Soc. Annual Conf., Singapore, 1988, pp. 509-521.
[26] J. Feng, Y. Hu, W. Chen, and C. C. Wen, “ZVS Analysis of Asymmetrical Half-Bridge Converter,” in Proc. 32rd Annual IEEE Power Electron., vol. 8, no. 4, pp. 423-430, Oct, 1993.
[27] J. A. Bassett, “DC/DC Converter Switching at Zero Voltage,” U.S. Patent 4 959 763, Sep. 25, 1990.
[28] C. P. Henze, D. S. Lo, and H. C. Martin, Jr., “Zero-Voltage Resonant Transition Switching Power Converter,” U.S. Patent 5 057 986, Oct. 15, 1991.
[29] B. Gu, J. Dominic, J. S. Lai, and H. B. Ma, “Hybrid Transformer ZVS/ZCS DC-DC Converter for Photovoltaic Microinverters,” in Applied Power Electronics Conf. and Exposition, 2013, pp. 16-22.
[30] 林建宇，隔離型混合切換返馳式轉換器之分析與設計，國立臺灣科技大學電子工程系研究所博士論文，2014年。
[31] 劉崇正，高功率半橋轉換器之設計與研製，逢甲大學電機工程學系研究所碩士論文，2005年。