傳統順向式轉換器常使用於500W以內的直直流電力轉換，提供弱電系統穩定的電源，當轉換器效率不佳時，會增加內部損耗功率，造成不必要的能源浪費。轉換器效率的高低，與同時出現在元件上的電壓、電流有很大的關係，而不必要的功率消耗，與頻率與導通時間有關，適當的改善技術，可以在電壓、電流、頻率與導通時間取得較佳的調協，達到節能與提高效率的效果。
本文透過IsSpice模擬與傳統順向式轉換器的實做成品，分析探討在能量轉換過程中損耗的原因，建立起數學模式，藉由數學模式的分析，解析傳導損失、切換損失與控制電路的消耗，並透過主動箝位、同步整流與脈衝跳躍技術的使用，將傳統順向式轉換器在輸出功率為50W到200W時的平均效率，由原先82.25%提升至90.45%；空載消耗，由原先的3W降至為1W，證明本文所使用的改善技術，可以達到改善效率的效果。

Traditional forward converter is often used in less than 500 watt AC to DC power converting. Provide low voltage system a stable power supply. When the converter efficiency poor will increase the internal power loss, resulting in unnecessary waste of energy. Converter efficiency of the high or low which relating to voltage and current at the same time on the components. And unnecessary power consumption will depend on the frequency and the turn on time. Therefore, the appropriate improvements technology will be able to voltage, current, frequency and turn on time to obtain best solution to achieve energy-saving effect.
This study used IsSpice simulation and the traditional forward converters finished product, to analysis and explore for energy transfer in the course of the power loss of the reasons, and establish a mathematical function. By the analysis of mathematical models to explore conduction loss, switching loss, controller dissipation. Through the active clamp, synchronous rectification, pulse skipping technology to let the converter the average efficiency of the conventer is increased from the original 82.25 percent to 90.45 percent in the output power of 50 W to 200 W. And no load consumption decrease from 3W to 1W. This shows the technology used in this study can achieve the goal of improving.

中文摘要 I
ABSTRACT II
目　錄 IV
圖 目 錄 VI
表 目 錄 IX
符 號 表 X
第一章 緒論 1
1.1 研究背景與動機 1
1.2 文獻回顧 5
1.3 研究方向 7
1.4 論文架構 8
第二章 順向式轉換器與改善技術 9
2.1 順向式轉換器 9
2.1.1 鐵芯的消磁 10
2.2 改善技術原理 15
2.2.1 共振技術 17
2.2.2 柔性切換技術 21
2.2.3 同步整流技術 24
第三章 傳統順向式轉換器的設計與分析 26
3.1 轉換器的設計 26
3.1.1 基本動作原理 26
3.1.2 元件規格設計 29
3.1.3 IsSpice模擬與成品實作 42
3.2 轉換器的損耗分析 51
3.2.1 傳導損失 52
3.2.2 切換損失 56
3.2.3 控制電路消耗 66
3.2.4 其他損失 69
第四章 傳統順向式轉換器的改善 72
4.1 降低空載消耗 75
4.2 減少能源轉換的損失 78
4.3 效率的提升 90
4.4 改善成果與測試討論 93
第五章 結論與未來展望 113
參考文獻 115

[1]http://en.wikipedia.org/wiki/Main_Page
[2]http://homework.wtuc.edu.tw/~wenlurg/
[3]International Energy Agency, ”2000 World energy outlook”, International Energy Agency, 2000
[4]California Energy Commission, ”2006 Appliance efficiency regulations”, California Energy Commission, 2006
[5]http://www.energystar.gov/
[6]European Commission, ”Code of conduct on energy efficiency of external power supplies”, European Commission , 2007
[7]聯合國，“「聯合國氣候變化綱要公約」京都議定書”，聯合國，1998
[8]李欣岳，”第三次工業革命來臨-綠金新商機全面啟動”，數位時代，第163期，民國96年
[9]Rich Fassler，”最佳化電源管理設計提高住宅用電效率”，電子工程專輯技術文庫，民國96年10月
[10]Rudy Severns, “The history of the forward converter”, Switching Power Magazine, pp. 20-22, July 2000.
[11]Kahou Wong, “How to choose switching controller for design”, ON Semiconductor Application Note, August 2005
[12]K. Harada, H. Sakamoto, “Switched snubber for high frequency switching”, Power Electronics Specialists Conference, 1990.
[13]J. Dekter, N. Machin, R. Sheehy, “Lossless active clamp for secondary circuits”, Telecommunications Energy Conference, 1998.
[14]V.Tuomainen, J. Kyyra, “Effect of resonant transition on efficiency of forward converter with active clamp and self-driven SR’s”, Power Electronics, IEEE Transactions on Volume 20, Issue 2, Mar 2005
[15]Bill Andreycak, “Active clamp and reset technique enhances forward converter performance”, Unitrode Seminar, 1994.
[16]Bor-Ren Lin, Huann-Keng Chiang, Chien-En Huang, Kao-Cheng Chen, D. Wang, “Analysis of an active clamp forward converter”, Power Electronics and Drives Systems, 2005.
[17]Bor-Ren Lin, Kevin Huang, David Wang, “Analysis, design and implementation of an active clamp forward converter with synchronous rectifier”, IEEE Transactions on circuits and systems-I: regular papers, Vol. 53, No. 6, JUNE 2006
[18]B.-R. Lin, C.E. Huang, D. Wang, “Analysis and implementation of a zero-voltage switching forward converter with a synchronous rectifier”, IEE Proceedings - Electric Power Applications, Vol. 152, No. 5 September 2005
[19]高裕翔，”高功率因數主動式箝位零電壓切換順向式轉換器之研製”，碩士論文，國立東華大學電機工程學系，民國96年
[20]張丁元，”主動箝位前向式轉換器之研製”，碩士論文，國立高雄應用科技大學電機工程系，民國96年
[21]張煌章，”具同步整流之主動箝位順向式轉換器分析與研製”，碩士論文，崑山科技大學電機工程系，民國96年
[22]邱榮貴，”零電壓切換之直流電源供應器製作” ，碩士論文，雲林科技大學電機工程系，民國95年
[23]王定宏，”磁集成設計於主動箝位順向式轉換器”，碩士論文，國立東華大學電機工程學系，民國94年
[24]吳昭漢，”主動箝位順向式轉換器之安定性研究”，碩士論文，義守大學電機工程學系，民國93年
[25]吳宗洵，”同步整流電路之逆流現象所引起的電磁干擾之研究”，碩士論文，義守大學電機工程學系，民國96年
[26]沈建成，”激磁電感量對主動式箝位式順向轉換器之影響” ，碩士論文，義守大學電機工程學系，民國93年
[27]M. Gildersleeve, H.P. Forghani-zadeh, G.A. Rincon-Mora, “A comprehensive power analysis and a highly efficient, mode-hopping DC-DC converter”, 2002 IEEE Asia-Pacific Conference on 6-8 Aug. 2002
[28]陳哲文，”運用阻抗轉換器於直流電壓調整器之設計與效率分析”，碩士論文，國立成功大學電機工程學系，民國96年
[29]張文雄，”低電壓大電流多相式降壓型電源轉換器之效率分析與設計”，碩士論文，輔仁大學電子工程學系，民國94年
[30]張裕青，“實驗分析ICs，MOSFETs，變壓器與其他設計因素對換流器零電壓切換的影響” ，碩士論文，元智大學電機工程學系，民國94年
[31]Neti R. M. Rao, ”Switched-mode power supply”, United States Patent 4253137, February 28, 1978
[32]劉育伶，“非浮接開關之零電流零電壓轉移柔切式升壓型電力轉換器之分析研製及控制器設計”，碩士論文，國立成功大學工程科學系，民國91年
[33]梁適安，”交換式電源供應器之理論與實務設計”，全華，2001
[34]賴建志，”具同步整流技術之零電流零電壓柔性切轉移順向式DC/DC電力轉換器研製”，碩士論文，國立成功大學工程科學系，民國93年
[35]Ferroxcube Company, “Product selection guide”, Ferroxcube Company Datasheet, 2005
[36]Chang Sung Corporation, “Magnetic powerd cores”, Chang Sung Corporation Datasheet, 2006
[37]鄭培璿，”電力電子分析與模擬”，全華，民國93年
[38]陳秋麟，林振宇，楊大勇，“降低切換式電源之待機功率損失”，崇茂科技技術專欄，民國92年
[39]Vrej Barkhordarian, “Power MOSFET basics”, International Rectifier Corporation Application Note, 2000.
[40]Barry W Williams, ”Power electronics devices - drivers, applications, and passive components”, McGraw-Hill, Sep. 1992
[41]Texas Instruments, “SLVP101, SLVP102, and SLVP103 buck converter design using the TL5001” Texas Instruments User Guide, 1998
[42]Brown Marty, ”Power supply cookbook”, Boston Mass Newnes, 2001
[43]Nippon Chemi-Con Corporation, “Aluminum electrolytic capacitors”, Nippon Chemi-Con Corporation Datasheet, 2007
[44]Lite-on Corporation, “High Density Mounting Type Photocoupler LTV817 Series”, Lite-on Corporation Datasheet, 2000
[45]H. A. Wheeler, “Formulas for the Skin Effect ” Proceedings of the IRE Volume 30, Issue 9, Sept. 1942 Page(s):412 – 424
[46]C. Patrick Yue, and S. Simon Wong, “Physical modeling of spiral inductors on silicon” IEEE Transactions on ElectronDevices, Vol. 47, No. 3, March 2000, pp. 560 560-568.
[47]Paolo Sandri, Maria Rosa Borghi, Luca Rigazio, “DC-to-DC converter functioning in a pulse skipping mode with low power consumption and PWM inhibit”, United States Patent 5745352, Apr. 1998, SGS-Thompson.
[48]Barry James Culpepper, Hidehiko Suzuki, “Switching DC-to-DC converter with discontinuous pulse skipping and continuous operating mode without external sense resistor”, United States Patent 6396252, May 2002, National Semiconductor.
[49]Naveed Majid, Tom Mobers, Erwin G. R. Seinen, “Low power stand-by for switched-mode power supply circuit with burst mode operation”, United States Patent 5812383, Sep. 1998, Philips Electronics.
[50]Ta-yung Yang, “PWM controller having off-time modulation for power converter”, United States Patent 6545882, Aug 2001, System General Inc.
[51]Japan Radio Corporation, ”External recirculating diodes”, JRC Application Note, 2000