本論文電路為輸入並聯、輸出串聯之高升壓轉換器，結合順向與返馳式轉換器，可於開關導通時具有電壓提升之特性，以提高轉換器之電壓轉換比。本架構轉換器為對稱性操作，二個主動開關為錯相式控制且共用同一箝位電容，並且利用此箝位電容達成漏電感能量回收。此轉換器開關在較大負載電流下，藉由共振使切換開關達成零電壓切換之特性，可降低開關之切換損失，另外，轉換器開關於較小負載電流條件下，切換開關則具有低電壓切換之特性。本文中將對常見之高升壓電路架構作簡介，並針對所提出之電路架構作特性分析與設計。最後，研製一輸入為24 V，輸出為200 V，輸出功率400 W之雛型電路以驗證理論分析之正確性。

In this thesis, a series input parallel output high step-up voltage converter is proposed. This converter combines the forward converter and the flyback converter to achieve high step-up voltage when the switch is turned on. The topology is operated in symmetry. The two active switches are interleavedly controlled, and utilize the same clamp capacitor to achieve leakage energy recycling. The switches of the proposed converter achieve zero voltage switching (ZVS) at full load and middle load, on the other hand, they achieve low voltage switching at condition of lower load current. In this research, conventional high step-up voltage converters and related topologies are firstly introduced, followed by characteristic analysis and design of the proposed converter, which is verified by a prototype circuit in the laboratory with 24V input and 200 V/400W output.

[1] R. J. Wai and R. Y. Duan, "High-efficiency power conversion for low power fuel cell generation system," IEEE Trans. Power Electron., vol. 20, no. 4, pp. 847-856, Jul. 2005.
[2] Q. Zhao, F. Tao, F. C. Lee, P. Xu, and J. Wei, "A simple and effective method to alleviate the rectifier reverse-recovery problem in continuous-current-mode boost converters," IEEE Trans. Power Electron., vol. 16, no. 5, pp. 649-658, Sep. 2001.
[3] F. L. Luo, "Seven self-lift DC-DC converters, voltage lift technique," IEE Proc. on Electric Power Applications, vol. 148, no. 4, pp. 329-338, Jul. 2001.
[4] B. Axelrod, Y. Berkovich, and A. Ioinovici, "Switched-capacitor/switched-inductor structures for getting transformerless hybrid DC-DC PWM converters," IEEE Trans. Circuits Syst. I, Fundam. Theory Appl., vol. 55, no. 2, pp. 687–696, Mar. 2008.
[5] B. Axelrod, Y. Berkovich, and A. Ioinovici, "Switched coupled-inductor cell for DC-DC converters with very large conversion ratio," in IEEE Industrial Electronics, IECON, Nov. 2006, pp. 2366-2371.
[6] F. L. Luo and H. Ye, "Positive output cascade boost converters," Proc. Inst. Elect.Eng., vol. 151, no. 5, pp. 590-606, Sep. 2004.
[7] T. J. Liang and K. C. Tseng, "Analysis of integrated boost-flyback step-up converter," Proc. Inst. Elect. Eng., vol. 152, no. 2, pp. 217-225, Mar. 2005.
[8] H. Wang, C. Gong, H. Ma and Y. Yan, “Research on a novel interleaved flyback DC/DC converter, " in Proc. IEEE Conf. Ind. Electron. Appl., 2006, pp. 1-5,
[9] EPRAC，「電力電子學綜論」，初版，全華圖書，民國九十三年。
[10] A. I. Pressman, Switching power Supply Design, McGraw-Hill Inc., 1998.
[11] R. W. Erickson and D. Maksimovic, Fundamentals of Power Electronics, Kluwer Academic Publishers, 2000.
[12] Marian. K. Kazimier, Pulse-Width Modulated DC-DC Power Converters, John Wiley & Sons, 2008.
[13] V. Tarateeraseth, T. Maneenopphon and W. Khan-ngern. “The comparison of EMI and lectrical performances of high frequency transformer windings for SMPS applications,” IEEE Proc. on PCC,, pp. 435-440, 2007.
[14] A. Hren, J. Korelic and M. Milanovic, “RC-RCD clamp circuit for ringing losses reduction in a flyback converter,” IEEE Trans. TCSII., vol. 53, pp. 369-373, May 2006.
[15] K. Harada and H. Sakamoto, “Switched snubber for high frequency switching,” IEEE Proc. on PESC., pp. 181-188, Jun. 1990.
[16] R. Petkov and L. Hobson, “Optimum design of a nondissipative snubber,” IEEE Proc. on PESC Record, vol. 2, pp. 1188-1195, 1994.
[17] C. Ji, K. M. Smith and K. M Smedley, “Cross regulation in flyback converters: solutions,” IEEE Proc. on IECON, vol. 1, pp. 174-179, 1999.
[18] C. S. Liao and K. M. Smedley, “Design of high efficiency flyback converter with energy regenerative snubber,” IEEE Proc. on APEC, pp. 796-800, 2008.
[19] C. M. F. Odulio, L. G. Sison and M. T. Escoto, “Regenerative clamp as reset winding in flyback converters for EDM applications,” IEEE Proc. on ICIT, vol. 1, pp. 510-513, 2004.
[20] R. Watson, F. C. Lee, and G. C. Hua, “Utilization of an active-clamp circuit to achieve soft switching in flyback converters,” IEEE Trans. on Power Electron., vol. 11, pp. 162-169, 1996.

[21] G. B. Koon and M. J. Youn, “A new zero voltage switching active clamp flyback converter,” IEEE Proc. on PESC, vol. 1, pp.508-510, 2005.
[22] B. R. Lin, H. K. Chiang, K. C. Chen and D. Wang, “Analysis, design and implementation of an active clamp flyback converter,” IEEE Proc. on PEDS, vol. 1, pp. 424-429, 2005.
[23] D. J. Perreault and J. G. Kassakian, “Distributed interleaving of paralleled power converters,” IEEE Trans. Circuits Syst. I, Fundam. Theory Appl., vol. 44, pp. 728-734, Aug. 1997.
[24] Texas Instrument Inc., “UC3825: High Speed PWN Controller,” 2007.