本論文致力研究及實作一台350W雙級降壓饋入式串聯諧振同步整流轉換器電路，第一級電路使用降壓轉換器電路，其目的是將輸入直流電壓380V降壓到300V。第二級為LLC串聯諧振同步整流轉換器電路，其目的是將第一級降壓電路的輸出電壓轉換成直流12V電壓輸出並提供給負載端。此LLC串聯諧振轉換器電路操作於固定頻率並具有零電壓切換及接近零電流切換區的特色，因此可實現電源高效率的特性。輸出直流12V電壓經由第一級降壓轉換器電路穩壓，其操作原理和設計考量將分析和詳述於本論文中。最後將實作一台350W降壓饋入式串聯諧振式轉換器電路，並利用實驗結果驗證其所提出設計理論的可行性。

This thesis aims to study and implement a two-stage buck-fed LLC series resonant converter with synchronous rectification. The first-stage buck converter is used to transfer DC voltage from 380V to 300V. The LLC series resonant converter with synchronous rectification supplies a 12V output voltage to the load. The LLC is operated at a fixed frequency with zero-voltage-switching and near to zero-current-switching features to achieve high efficiency performance. The output voltage is regulated by the pre-stage buck converter. The operating principles and design considerations are analyzed and discussed in details. A 350W prototype was designed and implemented. The experimental results are adown to verify the feasibility of the proposed scheme.

[1] F. C. Lee, “High-Frequency Quasi-Resonant and Multi-Resonant Converter Technologies,“ IEEE IECON, pp. 509-521, 1988.
[2] J. Dukdrik, P. Spanik and N. D. Trip, “Zero-Voltage and Zero-Current Switching Full-Bridge DC-DC Converter With Auxiliary Transformer”, IEEE Transactions on Power Electronics, Vol. 21, NO. 5, pp.1328-1335, Sep., 2006.
[3] J. Feng, Y. Hu, W. Chen and C. C. Wen, “ZVS Analysis of Asymmetrical Half-Bridge Converter,” IEEE PESC, Vol. 1, pp. 243-247, 2001.
[4] J. W. Baek, J. G. Cho, D. W. Yoo, G.H. Rim and H.G. Kim, “An Improved Zero Voltage and Zero Current Switching Full Bridge PWM Converter with Secondary Active Clamp”, IEEE PESC, pp. 948-954. 1998.
[5] J. G. Cho, J. A. Sabate and F. C. Lee, “Novel Full Bridge Zero-Voltage-Transition PWM DC/DC Converter for High Power Applications,” IEEE PESC, pp. 143-149, 1994.
[6] C. M. Wang, “A New Family of Zero-Current-Switching (ZCS) PWM Converter,” IEEE Transactions on Industrial Electronics, Vol. 52, pp. 1117-1125, 2005.
[7] A. K. S. Bhat, “Analysis and Design of a Modified Series Resonant Converter,” IEEE Transactions on Power Electronics, pp. 423-430, 1993.
[8] M. K. Kazimierczuk and S. Wong, “Frequency-Domain Analysis of Series Resonant Converter for Continuous Conduction Mode,” IEEE Transactions on Power Electronics, Vol. 6, pp. 270-279, 1992.
[9] M. K. Kazimierczuk and D. Czarkowski, “Resonant Power Converters,” Wiley-Interscience publication, ISBN 0-471-04706-6.
[10] J. P. Agrawal, K. Siri and C. Q. Lee, “Determination and Minimization of Cross Regulation in Multi-Output High Order SRC,” IEEE Circuits and Systems, Vol. 1, pp. 692-695. 1990.
[11] S. C. Wong, A. D. Brown, Y. S. Lee and S. W. Ng, “Parasitic Losses
Modeling of a Series Resonant Converter Circuit,” IEEE Circuits
and Systems, Vol. 1, pp. 921-924, 1997.
[12] R. Elferich and T. Duerbaum, “A New Load Resonant Dual Output Converter,” IEEE PESC, pp. 1319-1324, 2002.
[13] R. Liu and C. Q. Lee, “Analysis and Design of LLC-type Series Resonant Converter,” IEE Proc. Vol. 24, pp. 1517-1519, 1988.
[14] K. Siri and C. Q. Lee, “Constant Switching Frequency LLC-type Series Resonant Converter,” IEEE Circuits and Systems, Vol. 1, pp. 513-516, 1989.
[15] R. Liu, C. Q. Lee and A. K. Upadhyay, “Experimental Study of the LLC-type Series Resonant Converter,“ IEEE APEC, pp. 31-37, 1990.
[16] B. Yang, F. C. Lee, A. J. Zhang and G. S. Huang, “LLC Resonant Converter for Front End DC/DC Conversion,” IEEE APEC, pp. 1108-1112, 2002.
[17] B. Yang, “Topology Investigation for Front End DC/DC Power Conversion for Distributed Power,” Ph.D. Dissertation, Virginia Tech, 2003.
[18] Y. Liu, “High Efficiency Optimization of LLC Resonant Converter for Wide Load Range,’’Blacksburg, Virginia. December 4th,2007.

[19] B. Lu, W. Liu, Y. Liang, F. C. Lee and J. D. Van Wyk, ”Optimal Design Methodology for LLC Resonant Converter,” IEEE APEC, pp. 533–538. 2006.
[20] L. Yan, L. Wenduo, L. Bing and D. J. Wyk, “Design of Integrated Passive Component for a 1MHz 1KW Half-Bridge LLC Resonant Converter,” IEEE IAC, Vol. 3, pp. 2223-2228, 2005.
[21] 洪振傑，”高效能500W個人電腦電源供應器之研製”，國立台灣科技大學電子工程系碩士論文，民國九十八年。
[22] ON Semiconductor , “UC3843B-High Performance Current Mode Controllers”, Data Sheet,2007.
[23] Texas Instruments Inc, “UCC25600 8 pin high-Performance Resonant Mode Controller“, Data Sheet,2011.
[24] 吳健銘，”降壓同步倍流整流半橋整流器之研究”，國立成功大學電機工程系研究所碩士論文，民國九十三年。
[25] Y. Ye, C. Yan, J. Zeng and J. Ying, “A Novel Light Load Solution for LLC Series Resonant Converter,” IEEE INTELEC. Telecommunication Energy Conference, pp. 61-65, Setp. 30 - Oct. 4, 2007.
[26] 楊詠迪，”雙輸出串聯諧振轉換器研製”，國立台灣科技大學電子工程系碩士論文，民國九十六年。
[27] 謝儲仲，”寬輸入電壓範圍之雙組輸出半橋LLC串聯諧振轉換器研製” ，國立台灣科技大學電子工程系碩士論文，民國九十八年。
[28] 黃卓文，”半橋串聯諧振轉換器輕載非對稱單側責任週期調變策略研究”，國立台灣科技大學電子工程系碩士論文，民國九十八年。
[29] 鍾鎮龍，”雙變壓器雙諧振槽半橋串聯諧振轉換器研製”，國立台灣科技大學電子工程系碩士論文，民國九十九年。
[30] 陳建宇，” 二次側諧振槽串聯諧振轉換器頻率調變策略研究”，國立台灣科技大學電子工程系碩士論文，民國九十九年。
[31] International Rectifier IR1167, “IR1167 Advanced Smart Rectifier Control Ic”, Data Sheet,2009.
[32] International Rectifier IR1167, “IR1167 智能同步整流控制器應用手冊AN-1087”.