本文提出具有雙向功率轉換功能之六臂型三相市電併網換流器及每相為二臂型全橋式換流器的設計。文中以單極性弦式脈波寬度調變進行全橋式換流器的控制，並藉軟體數位鎖相迴路實現市電電壓角位置偵測，使功率因數接近1.0，且以電流及功率閉迴路控制，降低輸出穩態誤差。雙向功率轉換市電併網控制包括併網模式及整流模式:在併網模式下，負載潮流由直流側流至交流側，而在整流模式下，則由交流側流至直流側。另者，本文的三相六臂型換流器及功率閉迴路控制策略，亦可達成三相電壓不平衡時的個別單相定功率控制，且於市電瞬斷時提供一穩定獨立電壓源。
系統使用之32位元數位信號處理器(DSP，TMS320F28069)，其雙向功率轉換與三相併網控制軟體皆採C語言，可減少電路元件，提高可靠度。在併網模式下實測結果顯示，交流側輸出功率為6 kW，相電壓有效值與相電流峰值分別為220 V及12.9 A時，其電流總諧波失真率為2.63%，功率因數為0.99，效率為98%；而在整流模式下，直流側輸出功率及電流分別為6 kW 及15 A，直流電壓漣波低於1%，交流側相電壓有效值與相電流峰值分別為220 V及12.9 A，其電流總諧波失真率為2.93%，功率因數為0.99，效率為97%。實測結果驗證了本文系統之可行性。

This thesis presents the design of grid-connected bidirectional three-phase six-arm power converters, which consists of three single-phase, two-arm, full-bridge converters using unipolar sinusoidal pulse-width modulation control strategy for each phase. Grid voltage angle is detected by phase-lock loop software to raise power factor to be close to unity. Direct current as well as power closed-loop controls are introduced to reduce the steady-state error of AC signals. The bidirectional power conversion contains grid-connection and rectification modes with power flows from AC to DC and DC to AC sides, respectively. Analyses and experiments of separate single-phase constant power controls under unbalanced three-phase voltage are also given for both modes. In addition, the proposed system can serve as stable and independent voltage sources when power failure occurs.
The 32-bit digital signal processor, TMS320F28069, is adopted as system core. The control strategies are implemented by C language for reliability and complexity improvement. The experimental results in grid-connected mode show output power of 6 kW on AC side, yielding power factor of 0.99. The corresponding phase voltage and its peak current are 220 V and 12.9 A, respectively, with total harmonic distortion (THD) of 2.63% and overall system efficiency of 98%. Whereas, the experimental results in rectification mode give output power and current on DC side of 6 kW and 15 A, respectively, with DC voltage ripple within 1%. The corresponding phase voltage and its peak current are 220 V and 12.9 A, with the THD, power factor and overall system efficiency of 2.93%, 0.99 and 97%, respectively. The experimental results verify the feasibility of the system proposed.

[1] H. Shen, X. Li, L. Sun, Y. Zhu, W. Zhao and J. Feng, "Research on Control of Three-Phase Grid-Connection Inverter Under Conditions of Voltage Distortion," 2016 IEEE 8th International Power Electronics and Motion Control Conference (IPEMC-ECCE Asia), Hefei, pp. 924-927, 2016.
[2] R. S. Lai and K. D. T. Ngo, "A PWM Method for Reduction of Switching Loss in a Full-Bridge Inverter," IEEE Transactions on Power Electronics, vol. 10, no. 3, pp. 326-332, 1995.
[3] Y. Chen and X. Jin, "Modeling and Control of Three-phase Voltage Source PWM Rectifier," 2006 CES/IEEE 5th International Power Electronics and Motion Control Conference, Shanghai, pp. 1-4, 2006.
[4] C. B. Jacobina, V. F. M. B. Melo, N. Rocha and E. R. C. da Silva, "Six-Phase Machine Conversion System with Three- and Single-Phase Series Converters," IEEE Transactions on Industry Applications, vol. 50, no. 6, pp. 3846-3856, 2014.
[5] T. F. Wu, C. H. Chang, L. C. Lin, G. R. Yu and Y. R. Chang, "DC-Bus Voltage Control with a Three-Phase Bidirectional Inverter for DC Distribution Systems," IEEE Transactions on Power Electronics, vol. 28, no. 4, pp. 1890-1899, 2013.
[6] S. V. Araujo, P. Zacharias and R. Mallwitz, "Highly Efficient Single-Phase Transformerless Inverters for Grid-Connected Photovoltaic Systems," IEEE Transactions on Industrial Electronics, vol. 57, no. 9, pp. 3118-3128,2010.
[7] T. F. Wu, K. H. Sun, C. L. Kuo, M. S. Yang and R. C. Chang, "Design and Implementation of a 5 kW 1φ Bi-Directional Inverter with Wide Inductance Variation," 2010 IEEE Energy Conversion Congress and Exposition, Atlanta, GA, pp. 45-52, 2010.
 
[8] T. F. Wu, L. C. Lin, N. Yao, Y. K. Chen and Y. C. Chang, "Extended Application of D-Σ Digital Control to a Single-Phase Bidirectional Inverter with an LCL Filter," IEEE Transactions on Power Electronics, vol. 30, no. 7, pp. 3903-3911, 2015.
[9] 姜士凱，“預測型電流控制之雙向換流器研製”，國立中正大學電機工程研究所碩士論文，民國九十七年。
[10] Y. Chen and K. M. Smedley, "Parallel Operation of One-Cycle Controlled Three-Phase PFC Rectifiers," IEEE Transactions on Industrial Electronics, vol. 54, no. 6, pp. 3217-3224, 2007.
[11] 張瑞騏，“雙向換流器之功因修正模式數位化控制”，國立中正大學電機工程研究所碩士論文，民國九十九年。
[12] 賴日生“Fundamentals of DC-AC inverter”，工業技術研究院，2009。
[13] C. W. Chen, C. Y. Liao, K. H. Chen and Y. M. Chen, "Modeling and Controller Design of a Semiisolated Multiinput Converter for a Hybrid PV/Wind Power Charger System," IEEE Transactions on Power Electronics, vol. 30, no. 9, pp. 4843-4853, 2015.
[14] Y. Ito, Y. Zhongqing and H. Akagi, "DC Microgrid Based Distribution Power Generation System," The 4th International Power Electronics and Motion Control Conference, 2004. IPEMC 2004., Xi'an, pp. 1740-1745, 2004.
[15] Xiao-tian. F ,Ai-min. Z and Hang. Z, "Design and Implementation of The Software Phase-Locked Loop for Cascading Power Conversion Devices," The 27th Chinese Control and Decision Conference (2015 CCDC), Qingdao, pp. 6232-6236, 2015.
[16] L. Hadjidemetriou, E. Kyriakides, Y. Yang and F. Blaabjerg, "A Synchronization Method for Single-Phase Grid-Tied Inverters," IEEE Transactions on Power Electronics, vol. 31, no. 3, pp. 2139-2149, 2016.
 
[17] J. M. Guerrero, J. C. Vasquez, J. Matas, L. G. de Vicuna and M. Castilla, "Hierarchical Control of Droop-Controlled AC and DC Microgrids—A General Approach Toward Standardization," IEEE Transactions on Industrial Electronics, vol. 58, no. 1, pp. 158-172, 2011.
[18] D. Shuai and X. Zhang, "Input-output Linearization and Stabilization Analysis of Internal Dynamics of Three-Phase AC/DC Voltage-Source Converters," 2010 International Conference on Electrical Machines and Systems, Incheon, pp. 329-333, 2010.
[19] A. Camacho, M. Castilla, J. Miret, J. C. Vasquez and E. Alarcon-Gallo, "Flexible Voltage Support Control for Three-Phase Distributed Generation Inverters under Grid Fault," IEEE Transactions on Industrial Electronics, vol. 60, no. 4, pp. 1429-1441, 2013.
[20] M. Castilla, J. Miret, J. L. Sosa, J. Matas and L. G. d. Vicuña, "Grid-Fault Control Scheme for Three-Phase Photovoltaic Inverters With Adjustable Power Quality Characteristics," IEEE Transactions on Power Electronics, vol. 25, no. 12, pp. 2930-2940, 2010.
[21] B. Geetal., "Direct Instantaneous Ripple Power Predictive Control for Active Ripple Decoupling of Single-Phase Inverter," IEEE Transactions on Industrial Electronics, vol. 65, no. 4, pp. 3165-3175, 2017.
[22] D. B. Wickramasinghe Abeywardana, P. Acuna, B. Hredzak, R. P. Aguilera and V. G. Agelidis, "Single-Phase Boost Inverter-Based Electric Vehicle Charger with Integrated Vehicle to Grid Reactive Power Compensation," IEEE Transactions on Power Electronics, vol. 33, no. 4, pp. 3462-3471, 2017.
 
[23] A. Anzalchi, M. Moghaddami, A. Moghaddasi, A. I. Sarwat and A. K. Rathore, "A New Topology of Higher Order Power Filter for Single-Phase Grid-Tied Voltage-Source Inverters," IEEE Transactions on Industrial Electronics, vol. 63, no. 12, pp. 7511-7522, 2016.
[24] P. Rodriguez, A. V. Timbus, R. Teodorescu, M. Liserre and F. Blaabjerg, "Flexible Active Power Control of Distributed Power Generation Systems During Grid Faults," IEEE Transactions on Industrial Electronics, vol. 54, no. 5, pp. 2583-2592, 2007.
[25] S. Fukuda and T. Yoda, "A Novel Current-Tracking Method for Active Filters Based on a Sinusoidal Internal Model [For PWM Invertors]," IEEE Transactions on Industry Applications, vol. 37, no. 3, pp. 888-895, 2001.
[26] B. Yin, R. Oruganti, S. K. Panda and A. K. S. Bhat, "An Output-Power-Control Strategy for a Three-Phase PWM Rectifier Under Unbalanced Supply Conditions," IEEE Transactions on Industrial Electronics, vol. 55, no. 5, pp. 2140-2151, 2008.
[27] 龔振偉，“電壓估測法於三相不平衡系統變流器之應用”，國立臺灣科技大學電機工程研究所碩士論文，民國九十七年。
[28] 楊承翰，“電壓不平衡率之定義及電壓不平衡對系統與設備影響之研究”，國立臺灣科技大學電機工程研究所碩士論文，民國一百零三年。
[29] 鍾秉學，“單相及三相市電併聯之功率轉傳器研製”，國立臺灣科技大學電機工程研究所碩士論文，民國一百年。
[30] 李柏穎，“不平衡負載之線上型三相不斷電系統研製”，國立臺灣科技大學電機工程研究所碩士論文，民國一百零三年。
[31] IEEE Recommended Practice for Electric Power Distribution for Industrial Plants," IEEE Std 141-1993 , vol., no., pp.1-768, April 29 1994