傳統的返馳式轉換器，工作頻率操作大概在65 kHz，且切換會採取硬式切換方式，伴隨而來的是產生嚴重的電磁干擾與效率低落。本篇論文主要是研製一高頻的準諧振返馳式轉換器。此轉換器之工作頻率，設計在200 kHz，可以縮小磁性元件的體積。而使用準諧振返馳式轉換電路，具有電壓波谷切換特性，降低切換損耗與雜訊。二次側則搭配同步整流技術和蕭特基二極體，降低二次側傳導功率損耗和切換損耗，提高整體轉換效率。
最後本論文以交流輸入電壓範圍100 V至240 V、輸出直流電壓19V、輸出功率33W的規格做出一高頻準諧振返馳式轉換器，實際完成並測試驗證。效率最高可達90.5%，平均效率可到89%，最低待機損耗42mW，確實可符合現今所有能源法規及能源之星規範的要求。

The switching frequency of the conventional flyback converter is designed about 65kHz and the switching mode is hard switching, which is leading to a serious electromagnetic interference and low conversion efficiency. The purpose of the thesis is to develop a quasi-resonant flyback converter with high switching frequency. The switching frequency of this converter is designed about 200 kHz that could reduce the volume of the magnetic components. This quasi-resonant flyback converter which owns a voltage valley-switching characteristic can reduce switching loss and noise. The secondary side is designed with a synchronous rectification technique and schottky rectifier which could reduce both of the conduction loss and the switching loss on the secondary side, and it can improve the conversion efficiency.
In conclusion, the thesis implements to develop a high switching frequency quasi-resonant flyback converter which specifications include input voltage range of 100~240 Vac and output of 19 Vdc / 33 W. The power supply is implemented to test and verify with the 90.5% highest efficiency, 89% average efficiency and the 60mW low power loss at standby mode, which is meet the compliance with the EPA requirements and Energy Star regulations.

[1] 梁適安，"交換式電源供應器之理論與實務設計"，台北：全華科技圖書股份有限公司，1994。
[2] D. W. Hart 著，王順忠譯，"電力電子學"，台北，東華書局，1998。
[3] 梁適安，"高頻交換式電源供應器"，台北：全華科技圖書股份有限公司，1995。
[4] M. H. Rashid 著，張天錫譯，"電力電子學 第三版"，台北，東華書局，2004。
[5] 吳義利，"切換式電源轉換器：原理與實用設計技術(實例設計導向) "，文笙書局
[6] J. Zhang, X. Huang, X. Wu, and Z. Qian, "A High Efficiency Flyback Converter With New Active Clamp Technique," IEEE Trans. on Power Electron., vol. 25, no. 7, pp. 1775-1785, Jul. 2010.
[7] J. W. Kim, "Series Input Parallel Output Interleaved Flyback Converter with Regenerative Leakage Inductance Energy," in Proc. ECCE Asia, pp. 1347-1352, June 2012
[8] Y.-C. Hsieh , M.-R. Chen and H.-L. Cheng "An interleaved flyback converter featured with zero-voltage transition," IEEE Trans. Power Electron., vol. 26, no. 1, pp.79- 84 2011.
[9] G.-B. Koo, "A new valley-detection method for the quasi-resonance switching," in Proc. APEC, pp. 540-543, Feb. 2010.
[10] K. B. Park, C. E. Kim, G. W. Moon, and M. J. Youn, "PWM resonant single switch isolated converter," IEEE Trans. Power Electron., vol. 24, no. 8, pp.1876-1886, Aug 2009.
[11] K. Lin, R. Oruganti, and F. C. Lee, "Resonant switches topologies and characteristics," IEEE Trans. on Power Electronics, Vol. PE-2 No. 1, pp.62-74, 1987.
[12] 郭明豪，"準諧振返馳式轉換器研製"，碩士論文，國立台灣科技大學電機工程系，台北，2014。
[13] 林輝菖，"高效率準定頻準諧振返馳式轉換器"，碩士論文，國立台灣科技大學電子工程系，台北，2015。
[14] 孟祥玨，"薄型化高效率電源供應器之研製"，碩士論文，國立台北科技大學電機工程系，台北，2014。
[15] Panasonic, "PGA26E34HA GaN-Tr N-channel enhancement mode FET," Data Sheet, Rev. 002, 2018。
[16] Monolithic Power Systems, "MP6910A CCM/DCM Flyback Ideal Diode with Integrated 100V MOSFET for up to 2.5A Output," Data Sheet, Rev.1.0, September, 2017.
[17] ON Semiconductor, "NCP1340 High-Voltage, Quasi-Resonant, Controller Featuring Valley Lock-Out Switching," Data Sheet, Rev.3, June, 2017.
[18] Weltrend, "WT6630P USB Power Delivery Controller," Data Sheet, Rev.0.81, 2016.