臺灣博碩士論文加值系統

本文實現一應用於微電網之全數位化併網型雙向DC-AC轉換器。所提系統是以全橋轉換器作為主電路架構。此轉換器於DC-AC模式下輸出恆定交流電流以提供和電網併聯運轉。此轉換器於AC-DC模式下輸出恆定電壓以維持直流匯流排之穩定電壓。於AC-DC模式下，此轉換器可以作為無橋式功率因數修正器，因此，功率因數可以有效的提升。文中分析該轉換器於各操作模式下之等效電路以及動作原理。所分析之操作模式包含，變頻器模式、功率因數修正器模式以及轉態模式。此外，亦列出電路各元件之設計程序。再者，本文介紹變頻器模式下之多變結構控制法與其程式流程。文中亦介紹功率因數修正器模式下之平均電流控制法與其程式流程。最後，以實作一雙向轉換器，連接220vrms交流匯流排以及400V直流匯流排，額定功率為1kW，以實驗結果證明所提出之轉換器之可行性。

In this thesis, a full digital grid-connected bidirectional DC-AC converter based on H-bridge converter for microgrid system is implemented. Converter outputs constant AC current during DC-AC mode for parallel operation with power grid. Converter outputs constant voltage during AC-DC mode, in which maintains the voltage level of DC bus. During AC-DC mode, converter works as a bridgeless power factor corrector. Therefore, power factor can be increased. This thesis analyze each equivalent circuits and operating modes, including inverter mode, PFC mode, and transferring state. The processes of component parameter design are also presented in this thesis. Furthermore, control methods and program flow charts of variable structure system (VSS) control in inverter mode is described. Control methods and program flow charts of average current control in PFC mode are developed. Finally, a prototype converter with 220vrms AC bus, 400V DC bus, and the rated power is 1 kW is implemented. The experimental results demonstrate the feasibility of the implemented converter.

CONTENTS

CHINESE ABSTRACT I
ABSTRACT II
ACKNOWLEDGEMENT III
CONTENTS IV
LIST OF FIGURES VII
LIST OF TABLES X
CHAPTER 1 INTRODUCTION 1
1.1 Background and Motivation 1
1.2 Organization of Thesis 3
CHAPTER 2 REVIEW OF TOPOLOGIES 4
2.1 Inverter 4
2.1.1 Conventional inverter 4
2.1.2 Multilevel inverter 5
2.2 Power Factor Corrector 10
2.2.1 Definition of power factor 12
2.2.2 Passive power factor corrector 13
2.2.3 Active power factor corrector 15
2.2.4 Active power factor correction method 17
2.3 Conventional Bidirectional System 20
CHAPTER 3 ANALYSIS AND DESIGN OF A GRID-CONNECTED BIDIRECTIONAL DC-AC CONVERTER 22
3.1 System Description of Grid-connected Bidirectional DC-AC Converter 22
3.2 Grid-connected Bidirectional DC-AC Converter 23
3.3 Operating Principle in Inverter Mode 25
3.4 Operating Principle in Power Factor Corrector Mode 34
3.5 Operating Principle in Transferring State 42
3.5.1 Transferring principle from inverter mode to power factor corrector mode 42
3.5.2 Transferring principle from power factor corrector mode to inverter mode 48
3.6 Component Design 53
3.6.1 Inductor design 53
3.6.2 DC capacitor and AC capacitor design 54
3.6.3 Power switches design 55
CHAPTER 4 CONTROL OF GRID-CONNECTED BIDIRECTIONAL DC-AC CONVERTER 56
4.1 Introduction of Digital Control System 56
4.2 Microcontroller Unit Introduction 57
4.2.1 Introduction of micro-control unit TMS320F38035 57
4.2.2 Block diagram of microcontroller 59
4.3 Peripheral Circuits of Digital controller 59
4.4 Control Strategy and Implement in Inverter Mode 60
4.4.1 Conventional PI control 60
4.4.2 Variable structure system control 63
4.5 Control Strategy and Implement in Power Factor Corrector Mode 64
4.6 Program Flow Chart of the Digital Controlled Grid-connected Bidirectional DC-AC Converter 65
4.6.1 Flow chart of main program 65
4.6.2 Flow chart of interrupt subroutine 66
4.7 Code Parameters Design 72
4.7.1 Interrupt frequency and pulse width modulation module parameter design 72
4.7.2 Analog to digital converter module parameter design 74
CHAPTER 5 EXPERIMENTAL RESULTS 75
5.1 Specifications of the System 75
5.2 Experimental Results of Inverter Mode 76
5.3 Experimental Results of Power Factor Corrector Mode 81
5.4 Experimental Results of Transferring State 86
CHAPTER 6 CONCLUSIONS AND FUTURE WORKS 91
6.1 Conlusions 91
6.2 Future works 92
REFERENCES 93

REFERENCES

[1]K. Ishaque and Z. Salam, “A Deterministic Particle Swarm Optimization Maximum Power Point Tracker for Photovoltaic System Under Partial Shading Condition, IEEE Trans. Industrial Applications, vol. 60, no. 8, pp. 3195-3206, Aug. 2013.
[2]C. H. Chang, E. C. Chang, and H. L. Cheng, “A High-Efficiency Solar Array Simulator Implemented by an LLC Resonant DC–DC Converter, IEEE Trans. Power Electron., vol. 28, no. 6, pp. 3039-3046, Jun. 2013.
[3]S. Mishra, D. Ramasubramanian, and P. C. Sekhar, “A Seamless Control Methodology for a Grid Connected and Isolated PV-Diesel Microgrid, IEEE Trans. Power Systems, vol. 28, no. 4, pp. 4393-4404, Nov. 2013.
[4]T. S. Hwang, M. J. Tarca, and S. Y. Park, “Dynamic Response Analysis of DC–DC Converter with Supercapacitor for Direct Borohydride Fuel Cell Power Conditioning System, IEEE Trans. Power Electron., vol. 27, no. 8, pp. 3605-3615, Aug. 2012.
[5]J. M. Galvez and M. Ordonez, “Swinging Bus Operation of Inverters for Fuel Cell Applications With Small DC-Link Capacitance, IEEE Trans. Power Electron., vol. 30, no. 2, pp. 1064-1075, Feb. 2015.
[6]Y. Cho and J. S. Lai, “High-Efficiency Multiphase DC–DC Converter for Fuel-Cell-Powered Truck Auxiliary Power Unit, IEEE Trans.Veh. Tech., vol. 62, no. 6, pp. 2421-2429, Jul. 2013.
[7]P. C. Loh, D. Li, Y. K. Chai, and F. Blaabjerg, “Autonomous Control of Interlinking Converter With Energy Storage in Hybrid AC–DC Microgrid, IEEE Trans. Industrial Applications, vol. 49, no. 3, pp. 1374-1382, May/Jun. 2013.
[8]M. C. Molina and P. E. Mercado, “Power Flow Stabilization and Control of Microgrid with Wind Generation by Superconducting Magnetic Energy Storage, IEEE Trans. Power Electron., vol. 26, no. 3, pp. 910-922, Mar. 2011.
[9]A. Kahrobaeian and Y. A. I. Mohamed, “Robust Single-Loop Direct Current Control of LCL-Filtered Converter-Based DG Units in Grid-Connected and Autonomous Microgrid Modes, IEEE Trans. Power Electron., vol. 29, no. 10, pp. 5605-5619, Oct. 2014.
[10]Y. Gu, W. Li, and X. He, “Passivity-Based Control of DC Microgrid for Self-Disciplined Stabilization, IEEE Trans. Power Systems, vol. 30, no. 5, pp. 2623-2632, Sep. 2015.
[11]J. Kim, H. S. Song, and K. Nam, “Asymmetric Duty Control of a Dual-Half-Bridge DC/DC Converter for Single-Phase Distributed Generators, IEEE Trans. Power Electron., vol. 26, no. 3, pp. 973-982, Mar. 2011.
[12]H. Belloumi and F. Kourda, “Double Modulation Technique for a ZVS Self-Oscillating Half-Bridge Inverter, IEEE Trans. Power Electron., vol. 30, no. 4, pp. 1907-1913, Apr. 2015.
[13]G. R. Zhu, H. Wang, B. Liang, S. C. Tan, and J. Jiang, “Enhanced Single-Phase Full-Bridge Inverter with Minimal Low-Frequency Current Ripple, IEEE Trans. Industrial Electron. vol. 63, no. 2, pp. 937-943, Feb. 2016.
[14]I. Lee and G. W. Moon, “Analysis and Design of Phase-Shifted Dual H-Bridge Converter With a Wide ZVS Range and Reduced Output Filter, IEEE Trans. Industrial Electron., vol. 60, no. 10, pp, 4415-4426, Oct. 2013.
[15]F. Hong, J. Liu, B. Ji, Y. Zhou, J. Wang, and C. Wang, “Interleaved Dual Buck Full-Bridge Three-Level Inverter, IEEE Trans. Power Electron., vol. 31, no. 2, pp. 964-974, Feb. 2016.
[16]Y. Chen, D. Xu, and J. Xi, “Common-Mode Filter Design for a Transformerless ZVS Full-Bridge Inverter, IEEE Journal of Emerging and Selected Topics Power Electron., vol. 4, no. 2, pp. 405-413, Jun. 2016.
[17]J. C. Wu and C. W. Chou, “A Solar Power Generation System With a Seven-Level Inverter, IEEE Trans. Power Electron., vol. 29, no. 7, pp. 3454-3462, Jul. 2014.
[18]E. Najafi and A. H. M. Yatim, “Design and Implementation of a New Multilevel Inverter Topology, IEEE Trans. Industrial Electron., vol. 59, no. 11, pp, 4148-4154, Nov. 2012.
[19]K. K. Gupta and S. Jain, “A Novel Multilevel Inverter Based on Switched DC Sources, IEEE Trans. Industrial Electron., vol. 61, no. 7, pp, 3269-3278, Jul. 2014.
[20]H. Sepahvand, J. Liao, M. Ferdowsi, and K. A. Corzine, “Capacitor Voltage Regulation in Single-DC-Source Cascaded H-Bridge Multilevel Converters Using Phase-Shift Modulation, IEEE Trans. Industrial Electron., vol. 60, no. 9, pp, 3619-3626, Sep. 2013.
[21]P. Lezana, J. Rodriguez, and D. A. Oyarzun, “Cascaded Multilevel Inverter with Regeneration Capability and Reduced Number of Switches, IEEE Trans. Industrial Electron., vol. 55, no. 3, pp. 1059-1066, Mar. 2008.
[22]M. Marchesoni and P. Tensa, “Diode-clamped Multilevel Converters: A Practicable Way to Balance DC-link Voltages, IEEE Trans. Industrial Electron., vol. 49, no. 4, pp. 752-765, Aug. 2002
[23]X. Yuan and I. Barbi, “Fundamentals of a New Diode Clamping Multilevel Inverter, IEEE Trans. Industrial Electron., vol. 15, no. 4, pp.711-718, July 2000.
[24]M. Khazraei, H. Sepahvand, K. A. Corzine, and M. Ferdowsi, “Active Capacitor Voltage Balancing in Single-phase Flying-capacitor Multilevel Power Converters, IEEE Trans. Industrial Electron., vol. 59, no.2, pp.769-778, Feb. 2012.
[25]P. Roshankumar, P. P. Rajeevan, K. Mathew, K. Gopakumar, J. I. Leon, and L. G. Franquelo, “A Five-Level Inverter Topology with Single-DC Supply by Cascading a Flying Capacitor Inverter and an H-Bridge, IEEE Trans. Power Electron., vol. 27, no. 8, pp. 3505-3512, Aug. 2012.
[26]Y. Hinago and H. Koizumi, “A Switched-capacitor Inverter Using Series/parallel Conversion with Inductive Load, IEEE Trans. Industrial Electron., vol. 59, no. 2, pp.878-887, Feb. 2012.
[27]S. K. Kao, “Study on Capacitive and Inductive Load of Multilevel Inverter, Master thesis, Dept. Elect. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan, R.O.C, 2014.
[28]K. H. Kuo, “Design and Implementation of an Eleven-Level Inverter Using Coupled Inductor and Swithed Capcitor, Master thesis, Dept. Elect. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan, R.O.C, 2015.
[29]X. Liu, J. Xu, Z. Chen, and N. Wang, “Single-Inductor Dual-Output Buck–Boost Power Factor Correction Converter, IEEE Trans. Industrial Electron., vol. 62, no. 2, pp.943-952, Feb. 2015.
[30]M. Pahlevani, S. Pan, S. Eren, A. Bakhshai, and P. Jain, “An Adaptive Nonlinear Current Observer for Boost PFC AC/DC Converters, IEEE Trans. Industrial Electron., vol. 61, no. 12, pp.6720-6729, Dec. 2014.
[31]X. Xie, J. Li, K. Peng, C. Zhao, and Q. Lu, “Study on the Single-Stage Forward-Flyback PFC Converter With QR Control, IEEE Trans. Power Electron., vol. 31, no. 1, pp. 430-442, Jan. 2016.
[32]A. M. Pastor, E. V. Idiarte, A. C. Pastor, and L. M. Salamero, “Interleaved Digital Power Factor Correction Based on the Sliding-Mode Approach, IEEE Trans. Power Electron., vol. 31, no. 6, pp.4641-4653, Jun. 2016.
[33]Y. Jang and M. M. Jovanovi´c, “Bridgeless High-Power-Factor Buck Converter, IEEE Trans. Power Electron., vol. 26, no. 2, pp.602-611, Feb. 2011.
[34]J. W. Yang and H. L. Do, “Bridgeless SEPIC Converter With a Ripple-Free Input Current, IEEE Trans. Power Electron., vol. 28, no. 7, pp.3388-3394, Jul. 2013.
[35]B. Zhao, A. Abramovitz, and K. Smedley, “Family of Bridgeless Buck-Boost PFC Rectifiers, IEEE Trans. Power Electron., vol. 30, no. 12, pp.6524-6527, Dec. 2015.
[36]R. Davoodnezhad, D. G. Holmes, and B. P. McGrath, “A Novel Three-Level Hysteresis Current Regulation Strategy for Three-Phase Three-Level Inverters, IEEE Trans. Power Electron., vol. 29, no. 11, pp.6100-6109, Nov. 2014.
[37]J. P. Gegner and C. Q. Lee, “Linear Peak Current Mode Control: A Simple Active Power Factor Correction Control Technique, IEEE PESC 1996, pp. 196-202.
[38]H. J. Kim, G. S. Seo, B. H. Cho, and H. Choi, “A Simple Average Current Control With On-time Doubler for Multiphase CCM PFC Converter, IEEE Trans. Power Electron., vol. 30, no. 3, pp.1683-1693, Mar. 2015.
[39]X. Xu and A. Q. Huang, “A Novel Closed Loop Interleaving Strategy of Multiphase Critical Mode Boost PFC Converters, in Proc. 23rd IEEE APEC, Feb. 2008, pp. 1033-1038.
[40]Piccolo Microcontrollers, TMS320F2803x MCUs, Texas Instruments Inc.