在許多LED應用中，採用調光控制可以達到節能的訴求，然而在低調光時，因受限於開關的最小導通時間及切換頻率，致使無法達到寬廣的調光範圍。本論文設計與研製一降壓型寬範圍可調光發光二極體驅動電路，於不同調光準位時，降壓型轉換器採用一次側控制法則操作於準諧振模式、限頻模式、降頻模式及突發模式。在突發模式中，改變比例積分控制器之回授參數，仍可精確地估算輸出電流。因此，利用所提出之一次側控制法則，可達到理想的寬範圍線性調光。最後，本文實際研製一42 V/ 8 – 50 W之發光二極體驅動電路，調光範圍皆為100 % – 1 %，並可應用於市電輸入電壓90 – 264 Vrms。在額定功率8 W至50 W的應用中，於100 %至1 %調光時之電源電壓調整率皆小於5 %，全域輸入電壓的功率因數皆高於0.96，且THDi皆低於20 %，效率最高可達94.67 %。

For many LED applications, the dimming control is required in saving the energy consumptions. However, the wide-range dimming cannot be achieved due to the minimum on-time and switching frequency at low dimming level. In this thesis, a buck-type wide-range dimmable LED driver is designed and implemented. According to the different percentage of dimming, the buck converter can operate in QR mode, frequency limitation with the valley switching, frequency reduction mode, and burst mode with the primary-side control scheme. By changing the parameters of the PI controller, the LED current can still be estimated precisely in burst mode. Therefore, the ideally linear wide-range dimming can be achieved by the proposed primary-side control scheme. Finally, the buck-type LED driver with the universal input voltages 90 – 264 Vrms applied to 42 V/8 – 50 W LED lamps is implemented. The dimming range is from 100 % to 1 %. For the rated power 8 – 50 W applications, the line regulations at 100 % and 1 % dimming are both lower than 5 %. The power factor is higher than 0.96 and the total harmonic distortion is lower than 20 % in the universal input voltage range. The highest efficiency is 94.67%.

[1] International Energy Agency, “25 Energy Efficiency Policy Recommendations-2011 Update,” 2011. [Online]. Available:
http://www.iea.org/publications/freepublications/publication/25recom_2011.pdf
[2] R. Mehta, D. Deshpande, K. Kulkarni, S. Sharma, and D. Divan, “LEDs, A Competitive Solution for General Lighting Applications,” in Proc. Energy 2030 Conference, 2008. ENERGY 2008. IEEE, pp. 1 - 5, Nov. 2008.
[3] H. Liu, Y. Yu and X. Liu, “The research of humanized design of the LED landscape lighting lamp,” in Proc. IEEE CAIDCD, pp. 499 - 502, 2009.
[4] Y. K. Cheng and K. W. E. Cheng, “General Study for Using LED to Replace Traditional Lighting Devices,” in ICPESA, pp. 173 - 177, 2006.
[5] J. Y. Tsao, “Solid-state Lighting: Lamps, Chips, and Materials for Tomorrow,” Circuits and Devices Magazine, IEEE, vol. 20, no. 3, pp. 28 - 37, May/June, 2004.
[6] D. A. Steigerwald, J. C. Bhat, D. Collins, R. M. Fletcher, M. O. Holcomb,M. J. Ludowise, P. S. Martin, and S. L. Rudaz, “Illumination with solid state lighting technology,” IEEE J. Sel. Topics Quant. Electronics, vol. 8, no. 2, pp. 310 - 320, Mar./Apr. 2002.
[7] M. A. D. Costa, L. Schuch, L. Michels, C. Rech, J. R. Pinheiro, and G. H. Costa, “Autonomous Street Lighting System Based on Solar Energy and LEDs,” in IEEE ICIT, pp. 1143 - 1148, 2010.
[8] Y. K. Lo, K. H. Wu, K. J. Pai, and H. J. Chiu, “Design and Implementation of RGB LED Drivers for LCD Backlight Modules,” IEEE Trans. on Industrial Electronics, vol. 56, no. 12, pp.. 4862 - 4871, Dec. 2009.
[9] Limits for Harmonic Current Emissions, IEC 61000-3-2 Class C Standards, 2005.
[10] Y. Hu, L. Hubber, and M. M. Jovanović, “Single-Stage, Universal-Input AC/DC LED Driver with Current-Controlled Variable PFC Boost Inductor,” IEEE Trans. on Power Electronics, vol. 27, no. 3, pp. 1579 - 1588, Mar. 2012.
[11] T. J. Liang, S. C. Kang, C. A. Chen, R. L. Lin, and J. F. Chen, “Analysis and Design of Single-Stage Electronic Ballast with Bridgeless PFC Configuration,” in IEEE Proc. IECON’03, pp. 502 - 508, 2003.
[12] Y. C. Chuang, Y. L. Ke, H. S. Chuang, and C. C. Hu, “Single-Stage Power-Factor-Correction Circuit with Flyback Converter to Drive LEDs for Lighting Applications,” in IEEE IAS, pp. 1 - 9, 2010.
[13] I. H. Codas, C. S. Postiglione, C. B. Nascimento, and A. J. Perin, “A Single-Stage PDC Converter for Solid-State Lighting Applications,” in IEEE Proc. IECON’09, pp. 3490 - 3493, 2009.
[14] T. L. Chern, P. L. Pan, H. Y. Liao, and D. M. Tsay, “Single-Stage Buck Type LED Lighting Driver with New Design of Current Integral Control,” IEEE Conference on Industrial Electronics, pp. 2197 - 2202, Jun. 2011.
[15] H. Wu, Y. Zhang, M. Zhao, and H. Shen, “A Constant-on-Time Based Buck Controller with Active PFC for Universal Input LED System,” in IEEE PEDS, pp. 551 - 556, Jun. 2015.
[16] A. Godbole, B. Agrawal, and T. M. Leung, “Low Cost, Single Inductor Non-Isolated AC/DC LED Driver Design Using TPS92314A,” SLVA663, Texas Instruments, 2014.
[17] C. J. Chang and C. L. Chen, “An Isolated Output-Feedback Scheme with Minimized Standby Power for SMPS,” IEEE Trans. on Power Electronics, vol. 28, no. 11, pp. 5140 - 5146, Nov. 2013.
[18] C. Adragna, “Design Equations of High-power-factor Flyback Converters Based on The L6561,” AN1059, STMicroelectronics, 2000.
[19] Y. C. Li and C. L. Chen, “A Novel Prmary-Side Regulation Scheme for Single-Stage High-Power-Factor AC-DC LED Driving Circuit,” IEEE Trans. on Industrial Electronics, vol. 60, no. 11, pp. 4978 - 4986, Nov. 2013.
[20] V. Javadian and S. Kaboli, “Reliability Assessment of Some High Side MOSFET Drivers for Buck Converter,” in Electric Power and Energy Conversion Systems (EPECS), pp. 1 - 6, 2013.
[21] T. Modeer, S. Norrga, and H. P. Nee, “High-Voltage Tapped-Inductor Buck Converter Utilizing an Autonomous High-Side Switch,” IEEE Trans. on Industrial Electronics, vol. 62, no. 5, pp. 2868 - 2878, May 2015.
[22] B. M. Lim, Y. H. Ko, Y. S. Jang, and O. H. Kwon, “A 200-V 98.16%-Efficiency Buck LED Driver Using Integrated Current Control to Improve Current Accuracy for Large-Scale Single-String LED Backlighting Applications,” IEEE Trans. on Power Electronics, vol. 31, no. 9, pp. 6416 - 6427, 2015.
[23] X. Wu, J. Yang, J. Zhang, and M. Xu, “Design Considerations of Soft-Switched Buck PFC Converter with Constant On-Time (COT) Control,” IEEE Trans. on Power Electronics, vol. 26, no. 11, pp. 3411 - 3152, 2011.
[24] U.S Department of Energy, “Using LEDs to Their Best Advantage”, Jan. 2012.
[25] U.S Department of Energy, “LED Color Characteristics”, Jan. 2012.
[26] R. L. Lin and Y. F. Chen, “Equivalent Circuit Model of Light-Emitting-Diode for System Analysis of Lighting Drivers,” in IEEE Industry Applications Society Annual Meeting (IAS), pp. 1 - 5, 2009.
[27] W. Chen, S. N. Li, and S. Y. R. Hui, “A Comparative Study on the Circuit Topologies for Offline Passive Light-Emitting Diode (LED) Drivers with Long Lifetime & High Efficiency” in Energy Conversion Congress and Exposition (ECCE), pp. 724 - 730, 2010.
[28] X. Xie, M. Ye, Y. Cai, and J. Wu, “An Optocouplerless Two-Stage High Power Factor LED Driver,” in Applied Power Electronics Conference and Exposition (APEC), pp. 2078 - 2083, 2011.
[29] T. L. Chern, L. H. Liu, P. L. Pan, and Y. J. Lee, “Single-Stage Flyback Converter for Constant Current Output LED Driver with Power Factor Correction” in IEEE Conference on Industrial Electronics and Applications, pp. 2891 - 2896, 2009.
[30] L. Jia, D. Fang, and Y. F. Liu, “High Power Factor Single Stage Flyback Converter for Dimmable LED Driver” in Energy Conversion Congress and Exposition (ECCE), pp. 3231 - 3238, 2015.
[31] X. Xie, Z. Lan, and C. Zhao, “A New Primary Side Controlled High Power Factor Single-Stage Flyback LED Driver,” in Energy Conversion Congress and Exposition (ECCE), pp. 3575 - 3580, 2012.
[32] Y. Leng, Y. Wang, J. Jiang, and L. He, “A Primary Side Controlled Single-Stage Flyback LED Driver with High Power Factor and High Accuracy,” in Future Energy Electronics Conference (IFEEC), pp. 293 - 298, 2013.
[33] H. H. Chou, Y. S. Hwang, and J. J. Chen, “An Adaptive Output Current Estimation Circuit for a Primary-Side Controlled LED Driver,” IEEE Trans. on Power Electronics, vol. 28, no. 10, pp. 4811 - 4819, 2012.
[34] C. N. Wu, Y. L, Chen, and Y. M Chen, “Primary-Side Peak Current Measurement Strategy for High-Precision Constant Output Current Control,” IEEE Trans. on Power Electronics, vol. 30, no. 2, pp. 967 - 975, 2015.
[35] X. Xie, J. Wang, C. Zhao, Q. Lu, and S. Liu, “A Novel Output Current Estimation and Regulation Circuit for Primary Side Controlled High Power Factor Single-stage Flyback LED Driver,” IEEE Trans. on Power Electronics, vol. 27, no. 11, pp. 4602 - 4612, 2012.
[36] X. L. Chen, T. Y. Jiang, S. Y. Zhao, H. L. Zeng, and J. M. Zhang, “Evaluation of Primary Side Control Schemes for Flyback Converter with Constant Current Output,” in Applied Power Electronics Conference and Exposition (APEC), pp. 1859 - 1863, 2013.
[37] J. S. Li and T. J. Liang, K. H. Chen, and Y. J. Lu, “Primary-Side Controller IC Design for Quasi-Resonant Flyback LED Driver,” in Energy Conversion Congress and Exposition (ECCE), pp. 5308 - 5315, 2015.
[38] J. M. Zhang, H. L. Zeng, and X. K. Wu, “An Adaptive Blanking Time Control Scheme for An Audible Noise-Free Quasi-Resonant Flyback Converter,” IEEE Trans. on Power Electronics, vol. 26, no.10, pp. 2735 - 2742, Oct. 2011.
[39] J. M. Cui, X. F. Yu, L. Wu, W. J. Xu, H. B. Qin, and L. H. Shao, “The Control-loop Design of Quasi-resonant Flyback Converter for HI-bright LED Driver,” in Electrical and Control Engineering (ICECE), pp. 5045 - 5048, 2011.
[40] J. Park, Y. J. Moon, M. G. Jeong, J. G. Kang, S. H. Kim, J. C. Gong, C. Yoo, “QR Controller with Adaptive Switching Frequency Reduction Scheme for Flyback Converter” IEEE Trans. on Industrial Electronics, vol. 63, no. 6, pp. 3571 - 3581, 2016.
[41] NXP Semiconductors, “TEA18363LT GreenChip SMPS Control IC,” Dec. 2013.
[42] Texas Instruments, “LM2903 Low Power, Low-Offset Voltage, Dual Comparators.” Dec. 2014.
[43] Texas Instruments, “UCC37325 Dual 4-A Peak High Speed Low-Side Power MOSFET Drivers,” Sept. 2002.
[44] Texas Instruments, “TMS320F28335 Digital Signal Controllers (DSCs) Data Manual,” Sept. 2008.