為充分使用太陽光發電系統能源，低輸入電流漣波升降壓型直流轉換器常作為前級電路，以進行最大功率點追蹤(MPPT)控制。雖然現有文獻中亦提出許多電流漣波消除技術，然而透過這些技術將會增加額外元件，或電路複雜度及成本。因此，本論文針對指導教授潘晴財博士為紀念其父親潘恭先生(Mr. Kung Pan)百年冥誕，所提出之低輸入電流漣波升降壓型KP直流轉換器作更進一步探討與分析。
　　本論文之主要貢獻可歸納如下：首先，介紹此低輸入電流漣波升降壓型KP直流轉換器之工作模式，並進行理論分析。此工作模式介紹與理論分析皆包含轉換器操作於連續導通模式及不連續導通模式。分析之結果顯示，此轉換器於兩種導通模式下，不須額外濾波元件即能擁有低輸入電流漣波之特點。另外，部分能量不須經由開關切換模式可直接傳送至輸出端，更得以獲得較高效率。第二，本論文亦詳細推導此轉換器於連續導通模式，及不連續導通模式之數學模型。於連續導通模式下，不同於套用傳統隔離型變壓器模型，此電路套用自耦變壓器模型，以更加明確顯示此轉換器部分能量無須經由開關切換模式即能傳送至輸出端，以期獲得較高之效率。最後，實際製作輸出瓦數200瓦，輸出電壓48V之雛形電路。透過實驗結果與模擬波形，可驗證電路操作之可行性與正確性。此外，實際量測此轉換器之輸入電流漣波於滿載情況下為輸入電流之0.81%。最後，此轉換器操作於升壓模式下擁有最高效率為95.76%，降壓模式下之最高效率為96.16%。

　　For fully exploiting the available solar energy in a photovoltaic (PV) generating system, it normally requires a low input current ripple step up/down dc converter as a front stage for implementing the maximum power point tracking (MPPT) control. Although several techniques have been proposed to conquer the input current ripple problem in existing literature, they suffer from either adding extra elements or increasing circuit complexity. Therefore, the major motivation of this thesis is aimed at further study of a low input current ripple step up/down KP DC converter which was proposed by Prof. Pan in memory of his beloved father, Mr. Kung Pan (KP).
　　The main contributions of this thesis could be summarized as follows: First, The operational principles and the theoretical analyses of the converter operated in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM) are presented. It reveals the input current ripple of the converter in both CCM and DCM can be very small without extra filter elements. Besides, partial energy could be delivered to the output without switching mode operation which will result in efficiency enhancement. Second, the corresponding mathematical models for both CCM and DCM are derived in details. For CCM, an autotransformer model instead of the traditional isolation transformer is adopted in the equivalent circuit which can explicitly show the special feature of the converter. Finally, a laboratory prototype with rating 200W and 48V output voltage is constructed. Experimental results show high consistency with simulation results, and the measured input current ripple of the converter is about 0.81% of input current in full load. The maximum efficiencies for step up mode and step down mode are 95.76% and 96.16%, respectively.

Chinese Abstract　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 I
Abstract　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 　　　　　　　　　II
Acknowledgement　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 III
Table of Contents　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 IV
List of Figures　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 VI
List of Tables…　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 XI
CHAPTER 1 Introduction　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 1
1.1 Motivation　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 1
1.2 Literature Survey　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 3
1.3 Contributions of the Thesis　　　　　　　　　　　　　　　　　　　　　　　　　　 4
1.4 Outline of the Contents　　　　　　　　　　　　　　　　　　　　　　　　　　　 4
CHAPTER 2 Review of Step Up/Down Converters　　　　　　　　　　　　　　　 6
2.1 Introduction　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 6
2.2 Buckboost Converter　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　6
2.3 Cúk Converter　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 10
2.4 A Novel Buck-Boost Converter Combining KY and Buck Converters　　　 16
CHAPTER 3 Analysis of Low Input Current Ripple Step Up/Down KP Converter 24
3.1 Introduction　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 24
3.2 Zero Inductor Current Ripple Principle 　　　　　　　　　　　　　　　　　　　　25
3.3 Circuit Configuration and Operational Principles　　　　　　　　　　　　　 27
3.4 Converter Characteristics in CCM　　　　　　　　　　　　　　　　　　　　　　　 39
3.5 Converter Characteristics in DCM 　　　　　　　　　　　　　　　　　　　　50
CHAPTER 4 Modeling of Low Input Current Ripple Step Up/Down KP Converter 56
4.1 Introduction　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 56
4.2 Mathematical Model in CCM　　　　　　　　　　　　　　　　　　　　　　　　　　　　 56
4.3 Mathematical Model in DCM　　　　　　　　　　　　　　　　　　　　　　　　　　　 63
4.4 Converter Open-Loop Transfer Functions　　　　　　　　　　　　　　　　　　 68
CHAPTER 5 Implementation and Experimental Results　　　　　　　　　　　　 78
5.1 Introduction　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 78
5.2 Design Guidelines of Power Circuit　　　　　　　　　　　　　　　　　　　　　 79
5.3 Hardware Implementation　　　　　　　　　　　　　　　　　　　　　　　　　　 83
5.4 Experimental Results　　　　　　　　　　　　　　　　　　　　　　　　　　　　 85
CHAPTER 6 Conclusions　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 105
6.1 Conclusions　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 105
6.2 Recommended Future Research　　　　　　　　　　　　　　　　　　　　　　　　　　　 106
References……　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 108

[1] B. K. Bose, "Global Warming: Energy, Environmental Pollution, and the Impact of Power Electronics," Industrial Electronics Magazine, IEEE, vol. 4, pp. 6-17, 2010.
[2] J. W. Arnulf, "PV Status Report 2013," 2013.
[3] N. Femia, G. Petrone, G. Spagnuolo, and M. Vitelli, "Optimizing sampling rate of P&O MPPT technique," in Power Electronics Specialists Conference, 2004. PESC 04. 2004 IEEE 35th Annual, 2004, pp. 1945-1949 Vol.3.
[4] N. Femia, G. Petrone, G. Spagnuolo, and M. Vitelli, "Optimization of perturb and observe maximum power point tracking method," Power Electronics, IEEE Transactions on, vol. 20, pp. 963-973, 2005.
[5] L. Piegari and R. Rizzo, "Adaptive perturb and observe algorithm for photovoltaic maximum power point tracking," Renewable Power Generation, IET, vol. 4, pp. 317-328, 2010.
[6] D. Sera, L. Mathe, T. Kerekes, S. V. Spataru, and R. Teodorescu, "On the Perturb-and-Observe and Incremental Conductance MPPT Methods for PV Systems," Photovoltaics, IEEE Journal of, vol. 3, pp. 1070-1078, 2013.
[7] L. Fangrui, D. Shanxu, L. Fei, L. Bangyin, and K. Yong, "A Variable Step Size INC MPPT Method for PV Systems," Industrial Electronics, IEEE Transactions on, vol. 55, pp. 2622-2628, 2008.
[8] K. H. Hussein, I. Muta, T. Hoshino, and M. Osakada, "Maximum photovoltaic power tracking: an algorithm for rapidly changing atmospheric conditions," Generation, Transmission and Distribution, IEE Proceedings-, vol. 142, pp. 59-64, 1995.
[9] C. T. Pan, J. Y. Chen, C. P. Chu, and Y. S. Huang, "A fast maximum power point tracker for photovoltaic power systems," in Industrial Electronics Society, 1999. IECON'99 Proceedings. The 25th Annual Conference of the IEEE, 1999, pp. 390-393.
[10] S. J. Chiang, K. T. Chang, and C. Y. Yen, "Residential photovoltaic energy storage system," Industrial Electronics, IEEE Transactions on, vol. 45, pp. 385-394, 1998.
[11] H. Sugimoto and H. Dong, "A new scheme for maximum photovoltaic power tracking control," in Power Conversion Conference - Nagaoka 1997., Proceedings of the, 1997, pp. 691-696 vol.2.
[12] A. N. A. Ali, M. H. Saied, M. Z. Mostafa, and T. M. Abdel-Moneim, "A survey of maximum PPT techniques of PV systems," in Energytech, 2012 IEEE, 2012, pp. 1-17.
[13] T. Esram and P. L. Chapman, "Comparison of Photovoltaic Array Maximum Power Point Tracking Techniques," Energy Conversion, IEEE Transactions on, vol. 22, pp. 439-449, 2007.
[14] R. W. Erickson and D. Maksimovic, Fundamentals of power electronics: Springer, 2001.
[15] N. Mohan and T. M. Undeland, Power electronics: converters, applications, and design: John Wiley & Sons, 2007.
[16] M. Jabbari and H. Farzanehfard, "New Resonant Step-Down/Up Converters," Power Electronics, IEEE Transactions on, vol. 25, pp. 249-256, 2010.
[17] Q. Ling, X. Shaojun, and Z. Hui, "A Novel Family of PWM Converters Based on Improved ZCS Switch Cell," in Power Electronics Specialists Conference, 2007. PESC 2007. IEEE, 2007, pp. 2725-2730.
[18] I. D. Kim, S. H. Paeng, J. W. Ahn, E. C. Nho, and J. S. Ko, "New Bidirectional ZVS PWM Sepic/Zeta DC-DC Converter," in Industrial Electronics, 2007. ISIE 2007. IEEE International Symposium on, 2007, pp. 555-560.
[19] K. I. Hwu and Y. T. Yau, "Two Types of KY Buck-Boost Converters," Industrial Electronics, IEEE Transactions on, vol. 56, pp. 2970-2980, 2009.
[20] K. I. Hwu and T. J. Peng, "A Novel Buck-Boost Converter Combining KY and Buck Converters," Power Electronics, IEEE Transactions on, vol. 27, pp. 2236-2241, 2012.
[21] D. C. Hamill, "An efficient active ripple filter for use in DC-DC conversion," Aerospace and Electronic Systems, IEEE Transactions on, vol. 32, pp. 1077-1084, 1996.
[22] W. Shireen and H. Nene, "Active Filtering of Input Ripple Current to Obtain Efficient and Reliable Power from Fuel Cell Sources," in Telecommunications Energy Conference, 2006. INTELEC '06. 28th Annual International, 2006, pp. 1-6.
[23] N. K. Poon, J. C. P. Liu, C. K. Tse, and M. H. Pong, "Techniques for input ripple current cancellation: classification and implementation [in SMPS]," Power Electronics, IEEE Transactions on, vol. 15, pp. 1144-1152, 2000.
[24] Z. Di, F. Wang, R. Burgos, L. Rixin, and D. Boroyevich, "DC-Link Ripple Current Reduction for Paralleled Three-Phase Voltage-Source Converters With Interleaving," Power Electronics, IEEE Transactions on, vol. 26, pp. 1741-1753, 2011.
[25] P. Thounthong, P. Sethakul, Rae, x, S. l, and B. Davat, "Fuel Cell Current Ripple Mitigation by Interleaved Technique for High Power Applications," in Industry Applications Society Annual Meeting, 2009. IAS 2009. IEEE, 2009, pp. 1-8.
[26] S. J. Zhang and X. Y. Yu, "A Unified Analytical Modeling of the Interleaved Pulse Width Modulation (PWM) DC-DC Converter and Its Applications," Power Electronics, IEEE Transactions on, vol. 28, pp. 5147-5158, 2013.
[27] R. Martinelli and C. Ashley, "Coupled inductor boost converter with input and output ripple cancellation," in Applied Power Electronics Conference and Exposition, 1991. APEC '91. Conference Proceedings, 1991., Sixth Annual, 1991, pp. 567-572.
[28] Z. M. Feng, Z. Zhang, D. Li, M. Chen, and Z. M. Qian, "An input and output ripple free converter with a four-winding coupled inductor," in Applied Power Electronics Conference and Exposition (APEC), 2010 Twenty-Fifth Annual IEEE, 2010, pp. 935-939.
[29] M. J. Schutten, R. L. Steigerwald, and J. A. Sabate, "Ripple current cancellation circuit," in Applied Power Electronics Conference and Exposition, 2003. APEC '03. Eighteenth Annual IEEE, 2003, pp. 464-470 vol.1.
[30] B. Mahdavikhah, S. M. Ahsanuzzaman, and A. Prodic, "A hardware-efficient programmable two-band controller for PFC rectifiers with ripple cancellation circuits," in Industrial Electronics Society, IECON 2013 - 39th Annual Conference of the IEEE, 2013, pp. 3240-3245.
[31] K. I. Hwu and Y. T. Yau, "KY Converter and Its Derivatives," Power Electronics, IEEE Transactions on, vol. 24, pp. 128-137, 2009.
[32] S. Jian, D. M. Mitchell, M. F. Greuel, P. T. Krein, and R. M. Bass, "Averaged modeling of PWM converters operating in discontinuous conduction mode," Power Electronics, IEEE Transactions on, vol. 16, pp. 482-492, 2001.
[33] S. Cuk and R. D. Middlebrook, "A general unified approach to modelling switching DC-to-DC converters in discontinuous conduction mode," in Power Electronics Specialists Conference, 1977, pp. 36-57.
[34] V. Vorpérian, "Simplified analysis of PWM converters using model of PWM switch. II. Discontinuous conduction mode," Aerospace and Electronic Systems, IEEE Transactions on, vol. 26, pp. 497-505, 1990.