現今再生能源蓬勃發展，發電的型態從傳統電廠密集的集中式發電，慢慢轉變為發電量小、發電裝置遍布電網各地的分散式發電，使儲能系統、不斷電系統的需求上升，雙向交流-直流轉換器的應用範圍也更加廣泛，本論文研製之具下垂並聯控制雙向交流-直流轉換器可將能量雙向的傳送至交流側或直流側，使用四顆功率開關、一顆儲能電感、直流側電容以及交流側電容達成雙向能量傳輸，元件數較單向整流器與單向換流器組成的轉換器少。開關的切換方式採用圖騰柱式的切換策略，此切換法具有高效率與電磁干擾共模雜訊低的優點被廣泛應用在高功率轉換器上。控制方面本文除了電壓-電流回授的雙迴路控制，還加上了責任週期前饋控制，可以增加電流迴路的頻寬、減少總諧波失真，提高交流側的電流品質，達成單台3.3 kW輸出功率的雙向交流直流轉換器，整流模式輸出功率為後級直流-直流轉換器包含其損耗的輸入功率，預留了3.6 kW的餘裕，換流模式提供能量給交流側負載為獨立供電模式。在分散式發電中，如何同步弦波電壓並使功率平均分配成為了重要的課題，傳統換流模式的並聯方式是使用訊號傳輸線提供各轉換器相同的參考電壓，十分依賴訊號抗干擾的品質；下垂控制是無需使用通訊系統即可達成同步與功率分配的技術，由於少了長距離通訊的不穩定性大幅提升系統的考靠度，本文採用下垂控制達成換流模式兩台轉換器總功率6.6 kW的並聯獨立供電系統，使用德州儀器公司生產的TMS320F28035作為控制核心MCU，實現上述控制方法。

Currently, renewable energy is flourishing, and the generation of electricity is gradually shifting from the centralized power plants to decentralized power generation. Lead to an increased demand for energy storage systems and uninterrupted power supply systems. As a result, the application range of bidirectional AC-DC converters has become more extensive. In this thesis, a droop-controlled bidirectional AC-DC converter is developed, capable of bidirectional energy transfer to either the AC side or the DC side. It employs four power switches, one energy storage inductor, and DC and AC side capacitors to achieve bidirectional energy transfer, requiring fewer components than the converters composed of unidirectional rectifiers and inverters. The switching strategy is implemented using the totem-pole switching method, known for its high efficiency and low electromagnetic interference common-mode noise, which is widely used in high-power converters.In terms of control, this paper not only incorporates a dual-loop control using voltage and current feedback but also adds a duty-ratio feedforward control. The bidirectional AC-DC converter is designed to deliver a single unit of 3.3 kW output power in inverter mode, accounting for the input power losses of the subsequent DC-DC converter and reserving an extra 3.6 kW of margin in rectifier mode, providing energy to the AC side load in standalone power supply mode.In this paper, the droop control is utilized to achieve a parallel independent power supply system with two converters in inverter mode, having a total power of 6.6 kW.

[1] 經濟部能源局，再生能源發電量統計112年4月份月報，https://www.re.org.tw/information/statistics_more.aspx?i d=6058。
[2] Kim, Sangjin, Minho Kwon, and Sewan Choi. “Operation and control strategy of a new hybrid ESS-UPS system.” IEEE Transactions on Power Electronics 33.6 (2017): 4746-4755.
[3] Green, P. B. “Low Frequency Transformer Based SOHO UPS Design.” Infineon Technologies AG: Munich, Germany (2020).
[4] Khare, Sagar, and Mohammad Kamil. “Offline UPS Reference Design Using the dsPIC® DSC.” Microchip Technology AN1279 (2009).
[5] Lazzarin, Telles B., Guilherme AT Bauer, and Ivo Barbi. “A control strategy for parallel operation of single-phase voltage source inverters: analysis, design and experimental results.” IEEE Transactions on Industrial Electronics 60.6 (2012): 2194-2204.
[6] Shanxu, Duan, et al. “Parallel operation control technique of voltage source inverters in UPS.” Proceedings of the IEEE 1999 International Conference on Power Electronics and Drive Systems. PEDS'99 (Cat. No. 99TH8475). Vol. 2. IEEE, 1999.
[7] Guerrero, Josep M., et al. “Output impedance design of parallel-connected UPS inverters with wireless load-sharing control.” IEEE Transactions on industrial electronics 52.4 (2005): 1126-1135.
[8] Xu, Shungang, and Jianping Xu. “Parallel control strategy of single-phase inverter based on virtual impedance.” 2010 International Conference on Communications, Circuits and Systems (ICCCAS). IEEE, 2010.
[9] 陳奕誠，應用於傳輸線阻抗不確定性之單相換流器並聯系統雙層迴路分流控制，國立交通大學電控工程研究所碩士論文，民國108年。
[10] Liu, Bo, et al. “Design of ac/dc converter for bidirectional on-board battery charger with minimizing the amount of SiC MOSFET.” 2017 IEEE Transportation Electrification Conference and Expo, Asia-Pacific (ITEC Asia-Pacific). IEEE, 2017.
[11] Sheng-Yang Yu, Xun Gong, Gangyao Wang, and Manish Bhardwaj, “Designing a High-Power Bidirectional AC/DC Power Supply Using SiC FETs,” 2020 Texas Instruments Power Supply Design Seminar SEM2400 Topic 2, TI Literature Number：SLUP393.
[12] Ye, Haoyi, et al. “Common mode noise modeling and analysis of dual boost PFC circuit.” INTELEC 2004. 26th Annual International Telecommunications Energy Conference. IEEE, 2004.
[13] High Efficiency, C. C. M. “Bridgeless Totem Pole PFC Design Using GaN E-HEMT.” GaN Syst., Ottawa, ON, Canada, GS665BTP-REF Rev170905 (2017).
[14] STMicroelectronics, “Getting started with the STEVAL-DPSTPFC1 3.6 kW PFC totem pole with inrush current limiter reference design,” User manual, UM2792-Rev 2-June 2022.
[15] Texas Instruments, “4-kW, Single-Phase Totem Pole PFC Reference Design With C2000 and GaN,” Design Guide：TIDA-010203.
[16] Algaddafi, Ali, et al. “Comparing the performance of bipolar and unipolar switching frequency to drive DC-AC Inverter.” 2016 International Renewable and Sustainable Energy Conference (IRSEC). IEEE, 2016.
[17] Texas Instruments, “Voltage Source Inverter Reference Design,” Design Guide：TIDM-HV-1PH-DCAC.
[18] Todd, Philip C. “UC3854 controlled power factor correction circuit design.” UNITRODE application note U-134 (1999): 10-303.
[19] Van de Sype, David M., et al. “Duty-ratio feedforward for digitally controlled boost PFC converters.” IEEE Transactions on Industrial Electronics 52.1 (2005): 108-115.
[20] Van de Sype, David M., et al. “Small-signal Laplace-domain analysis of uniformly-sampled pulse-width modulators.” 2004 IEEE 35th Annual Power Electronics Specialists Conference (IEEE Cat. No. 04CH37551). Vol. 6. IEEE, 2004.
[21] Sun, Bosheng. “How to reduce current spikes at AC zero-crossing for totem-pole PFC.” Texas Instruments Analog Applications Journal (2015).
[22] Ma, Xuejun, et al. “Control method with digital PI dual close-loop for inverter.” 2007 International Conference on Electrical Machines and Systems (ICEMS). IEEE, 2007.