单级三相式光伏并网逆变器研究
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摘要
随着新能源技术的迅速发展,光伏发电逐渐得到各国政府的广泛关注和大力支持,大容量光伏并网发电站成为太阳能开发的一种重要形式,研制高效、稳定、安全的三相光伏并网逆变器是建立大容量光伏电站的技术基础。为此,本文针对单级三相式光伏并网逆变器控制系统进行了深入研究。
首先通过建立单级三相式光伏并网逆变器在同步旋转坐标系下的数学模型,简述了传统PI控制技术原理及控制器参数设计。针对电流PI控制暂态响应速度慢的缺点,提出了一种适用于矢量控制系统的无差拍电流控制器,通过电流预测消除控制延时的影响,仿真和实验结果表明了该控制器的有效性。
最大功率点追踪技术是提高光伏逆变器效率的关键。本文根据光伏电池电气模型提出了一种基于光伏阵列外特性的建模方法,仿真结果表明该方法能够模拟光伏阵列输出非线性特点;叙述分析了传统追踪算法的原理及优缺点,提出了一种变步长电导增量法;将模糊控制理论引入到追踪算法中,提出了一种模糊控制器,该控制器鲁棒性强,追踪速度快、精度高,仿真结果验证了其有效性。
孤岛效应是分布式发电系统中的常见现象,准确快速检测孤岛状态成为光伏并网逆变器必备功能。本文首先介绍传统孤岛检测算法原理,针对被动式孤岛检测存在检测盲区的缺点,提出了一种适用于三相并网逆变器的主动频率偏移算法,该算法通过电流矢量角控制实现孤岛状态下系统接入点电压频率正反馈,进而检测出孤岛。仿真及实验结果表明该算法能够在功率匹配情况下仍然够迅速检测出孤岛的存在。
搭建了一套单级三相式光伏并网逆变器,辅以光伏模拟直流源、孤岛检测装置进行相应功能验证。详细介绍了逆变器控制系统软硬件组成,实验完成了并网控制,成功实现功率解耦;采用变步长电导增量法完成了最大功率点追踪;按照孤岛检测标准进行了逆变器反孤岛功能测试,验证了提出的主动检测法的有效性。
With the development of photovoltaic industry, the photovoltaic power generation system gets wide concern and substantial support from urge governments. Developing three-phase grid-connected solar inverters of great efficiency, stability and security is the technical foundation for building high-capacity solar power station, which is an important part of photovoltaic power generation. This paper mainly conducts the research on control system for single-stage three-phase grid connected photovoltaic inverters.
By building the mathematical model under synchronization reference frame, the traditional PI control principle for the inverter was introduced, including the design of control parameters. Due to drawbacks of PI current controller, which mainly lie in the slow transient response, a deadbeat current controller suitable for the vector control system was proposed. A current prediction algorithm was introduced to compensate the control delays introduced by digital controller, and the effectiveness of this deadbeat controller is verified by the simulation and experimental results.
Maximum power point tracking (MPPT) technology is the key to improvement of photovoltaic inverters’efficiency. According to the PV array’s electric model, a PV array simulation model was established by using its output characteristics, which could mimic the nonlinear characteristic of PV array output. The principles of traditional MPPT algorithms, whose advantages and disadvantages are both introduced, were demonstrated, future more, a novel variable incremental conductance algorithm was proposed. Finally, fuzzy control theory was introduced into the MPPT algorithm, which guaranteed the robustness, rapidity and high-precision of the MPPT controller, and its effectiveness was verified by simulation results.
Fast and accurate detection of islanding conditions, which is a common phenomenon for distributed generation systems, is the necessary function for grid connected PV inverters. This paper introduced the principles of traditional island detection algorithm. A novel active frequency drift (AFD) algorithm, which could introduce frequency passive feedback by changing current vector angle, was proposed for three phase inverter to eliminate the non-detection zone of passive island detection method. The simulation and experimental results proved that this algorithm could detect island even under power match conditions.
A single stage three phase PV inverter was established, which was functionally tested with DC voltage source and islanding device, and both the software and the hardware of the inverter were introduced in details. The grid generation experiment was conduced to realize the power decoupling control, and the effectiveness of variable step MPPT algorithm was also verified experimentally. An islanding experiment was designed according to island detection standard, which finally proved that the novel AFD algorithm works in the real PV system.
首先通过建立单级三相式光伏并网逆变器在同步旋转坐标系下的数学模型,简述了传统PI控制技术原理及控制器参数设计。针对电流PI控制暂态响应速度慢的缺点,提出了一种适用于矢量控制系统的无差拍电流控制器,通过电流预测消除控制延时的影响,仿真和实验结果表明了该控制器的有效性。
最大功率点追踪技术是提高光伏逆变器效率的关键。本文根据光伏电池电气模型提出了一种基于光伏阵列外特性的建模方法,仿真结果表明该方法能够模拟光伏阵列输出非线性特点;叙述分析了传统追踪算法的原理及优缺点,提出了一种变步长电导增量法;将模糊控制理论引入到追踪算法中,提出了一种模糊控制器,该控制器鲁棒性强,追踪速度快、精度高,仿真结果验证了其有效性。
孤岛效应是分布式发电系统中的常见现象,准确快速检测孤岛状态成为光伏并网逆变器必备功能。本文首先介绍传统孤岛检测算法原理,针对被动式孤岛检测存在检测盲区的缺点,提出了一种适用于三相并网逆变器的主动频率偏移算法,该算法通过电流矢量角控制实现孤岛状态下系统接入点电压频率正反馈,进而检测出孤岛。仿真及实验结果表明该算法能够在功率匹配情况下仍然够迅速检测出孤岛的存在。
搭建了一套单级三相式光伏并网逆变器,辅以光伏模拟直流源、孤岛检测装置进行相应功能验证。详细介绍了逆变器控制系统软硬件组成,实验完成了并网控制,成功实现功率解耦;采用变步长电导增量法完成了最大功率点追踪;按照孤岛检测标准进行了逆变器反孤岛功能测试,验证了提出的主动检测法的有效性。
With the development of photovoltaic industry, the photovoltaic power generation system gets wide concern and substantial support from urge governments. Developing three-phase grid-connected solar inverters of great efficiency, stability and security is the technical foundation for building high-capacity solar power station, which is an important part of photovoltaic power generation. This paper mainly conducts the research on control system for single-stage three-phase grid connected photovoltaic inverters.
By building the mathematical model under synchronization reference frame, the traditional PI control principle for the inverter was introduced, including the design of control parameters. Due to drawbacks of PI current controller, which mainly lie in the slow transient response, a deadbeat current controller suitable for the vector control system was proposed. A current prediction algorithm was introduced to compensate the control delays introduced by digital controller, and the effectiveness of this deadbeat controller is verified by the simulation and experimental results.
Maximum power point tracking (MPPT) technology is the key to improvement of photovoltaic inverters’efficiency. According to the PV array’s electric model, a PV array simulation model was established by using its output characteristics, which could mimic the nonlinear characteristic of PV array output. The principles of traditional MPPT algorithms, whose advantages and disadvantages are both introduced, were demonstrated, future more, a novel variable incremental conductance algorithm was proposed. Finally, fuzzy control theory was introduced into the MPPT algorithm, which guaranteed the robustness, rapidity and high-precision of the MPPT controller, and its effectiveness was verified by simulation results.
Fast and accurate detection of islanding conditions, which is a common phenomenon for distributed generation systems, is the necessary function for grid connected PV inverters. This paper introduced the principles of traditional island detection algorithm. A novel active frequency drift (AFD) algorithm, which could introduce frequency passive feedback by changing current vector angle, was proposed for three phase inverter to eliminate the non-detection zone of passive island detection method. The simulation and experimental results proved that this algorithm could detect island even under power match conditions.
A single stage three phase PV inverter was established, which was functionally tested with DC voltage source and islanding device, and both the software and the hardware of the inverter were introduced in details. The grid generation experiment was conduced to realize the power decoupling control, and the effectiveness of variable step MPPT algorithm was also verified experimentally. An islanding experiment was designed according to island detection standard, which finally proved that the novel AFD algorithm works in the real PV system.
引文
[1]赵争鸣,刘建政,孙晓瑛,等.太阳能光伏发电及其应用[M].北京:科学出版社, 2005: 1-8.
[2]冯垛生,宋金莲,赵慧,等.太阳能发电原理与应用[M].北京:人民邮电出版社, 2007: 3-32.
[3]罗运俊,何梓年,王长贵.太阳能利用技术[M].北京:化学工业出版社. 2005: 12-23.
[4]陆晓楠,黄立培,杨仲庆.中国光伏发电产业的现状及发展趋势[J].高科技与产业化, 2009, (02): 42-43.
[5]施钰川.太阳能原理与技术[M].西安:西安交通大学出版社, 2008: 18-32
[6] The PV industry 2009: in search of stability and sustainability, Renewable Energy World, 2009.
[7]侯岩.全球光伏电池的生产趋势及市场分析[J].电源技术2011 (3): 338-339.
[8]沈辉,舒碧芬,闻立时.我国太阳能光伏产业的发展机遇与战略对策[J].电池, 2005, 35(6): 430-432.
[9]钱伯章太阳能技术与应用[M].北京:科学出版社2010: 1-10
[10] Luque A, Hegedus S. Handbook of Photovoltaic Science and Engineering[M]. UK, Wiley, 2003: 11-19.
[11]吴理博.光伏并网逆变系统综合控制策略研究及实现[D].清华大学电气工程, 2006: 17-21.
[12]李丽,张贵友,陈人杰,陈实,吴锋.太阳能电池及关键材料的研究进展[J]化工新型材料, 2008,(11): 21-23.
[13]蒋荣华,邓良平,冯地直,等.我国硅太阳能电池的新发展[J].新材料产业, 2008, (02): 39-46.
[14] IEEE Std 929-2000. IEEE Recommended Practice for Utility Interface of Photovoltaic (PV) Systems. NY, USA: IEEE, 2000.
[15] Cody G, Tiedje T.A learning curve approach to projecting cost and performance in thin film photovoltaic[C]. Photovoltaic Specialists Conference, Conference Record of the Twenty Fifth IEEE. Washington: IEEE, 1996: 1521-1524.
[16]陈维,沈辉,邓幼俊,舒杰.光伏发电系统中逆变器技术应用及展望[J].电力电子技术. 2006. (04): 130-133.
[17] Meinhardt M, Cramer G. Past, present and future of grid connected photovoltaic and hybrid power systems [C]. Proceedings of IEEE Power Engineering Society Summer Meeting, USA, 2000: 1283-1288.
[18]吴理博,赵争鸣,刘建政,等.具有无功补偿功能的单级式三相光伏并网系统[J].电工技术学报, 2006, 21(1): 28-32.
[19] Hussein K H, Muta I, Hoshino T, et al. Maximum photovoltaic power tracking: an algorithm for rapidly changing atmospheric conditions[J]. Generation, Transmission and Distribution, IEE Proceedings-, 1995, 142(1):59-64.
[20]曾光奇,胡均安,王东,等.模糊控制理论与工程应用[M].华中科技大学出版社. 2006: 18-21.
[21]韩峻峰,李玉惠.模糊控制技术[M].重庆大学出版社2003: 34-36.
[22] Tae-Yeop K, Ho-Gyun A, Seung Kyu P, et al. A novel maximum power point tracking control for photovoltaic power system under rapidly changing solar radiation[C]. IEEE International Symposium on Industrial Electronics, 2001. Proceedings. ISIE 2001. Pusan: IEEE, 2001: 1011-1014.
[23]张崇巍,张兴. PWM整流器及其控制[M].北京,机械工业出版社. 2005: 21-30.
[24] Hoffmann, Winfried. PV solar electricity: Market growth and perspective[J]. Solar Energy Meterials and Solar Cells, 2006, 90(18): 3285-3311.
[25]陈伯时.电力拖动自动控制系统——运动控制系统[M].机械工业出版社, 2003: 197-200.
[26] Marian P Kazmierkowski, Luigi Malesani. Current Control Techniques for Three-phase Voltage Source PWM Converter: A Survey[J]. IEEE Trans. on Industrial Electronics, 1998, 45(5): 691~703.
[27] DK Min, SC Ahn, DS Hyun. Control of A PWM Converter In Different Input Voltage Conditions[C]. Proceedings of IEEE IECON Conference, New Orleans, 1997: 882~887.
[28]顾和荣,杨子龙,邬伟扬.并网逆变器输出电流滞环跟踪控制技术研究[J].中国电机工程学报, 2006, (09): 108-112.
[29] Kang B J,Liaw C M.Robust hysteresis current-controlled PWM scheme with fixed switching frequency[J]. IEE Proceedings- Electric Power Applications,2001,148(6): 503-512.
[30] Q. Zeng, L. Chang, and P. Song, SVPWM-based current controller with grid harmonic compensation for three-phase grid-connected VSI[C], in Proc. IEEE 35th Annu. PESC, 2004: 2494–2500.
[31] Hyung-Tae Moon, Hyun-Soo Kim, Myung-Joong youn. A discrete-time predictive current control for PMSM [J]. IEEE Trans, Power Electronics, 2003, 18(1): 464-472.
[32] K Nishida, M Rukonuzzman, M Nakaoka. Advanced current controlimplementation with robust deadbeat algorithm for shunt single-phase voltage-source type active power filter[J]. IEE Proc, Electric Power Applications, 2004, 151(3): 283-288.
[33]李春龙,沈颂华,卢家林,等.具有延时补偿的数字控制在PWM整流器中的应用[J].中国电机工程学报. 2007 (7): 94-97.
[34] K Nishida, M Rukonuzzman, M Nakaoka. Advanced current control implementation with robust deadbeat algorithm for shunt single-phase voltage-source type active power filter[J]. IEE Proc. Electric Power Applications, 2004, 151(3): 283-288.
[35] J. L. Agorreta, L. Reinaldos, R. Gonzalez, M. Borrega, J. Balda, and L. Marroyo. Fuzzy switching technique applied to PWM boost converteroperating in mixed conduction mode for PV systems[J]. IEEE Trans, Ind. Electron, 2009 56(11): 4363–4373.
[36]周德佳,赵争鸣,吴理博.基于仿真模型的太阳能光伏电池阵列特性的分析[J].清华大学学报. 2007 47(7): 1109-1112.
[37] Hussein K H, Muta I, Hoshino T, et al. Maximum photovoltaic power tracking: an algorithm for rapidly changing atmospheric conditions. Generation, Transmission and Distribution, IEE Proceedings, 1995, 14, PV Systems. IEEE Std 929-2000. NY, USA.
[38]程启明,王映斐,程伊曼,等.分布式发电并网系统中孤岛检测方法的综述研究[J].电力系统保护与控制. 2011, 39(6): 147-149.
[39] Moziza C J. Interconnection protection of IPP generators at commercial industrial facilities [J]. IEEE Trans on Industry Applications, 2001, 37(3): 681-689.
[40] Ropp M, Larson D, Meendering S, et al. Discussion of a power line carrier communications-based anti-islanding scheme using a commercial automatic meter reading system [C]. Proceedings of the 4th IEEE Conference on Photovoltaic Energy Conversion. 2007, 2: 2351-2354.
[41] Mekhief S, Rahim N A. Implementation of grid-connected photovoltaic system with power factor control and islanding detection[C]. Power Eleetronics Specialists Conference 2004, PESC04, 2004 IEEE 35th Annual. AaChen, Germany: IEEE. 2004: 1409-1412.
[42] Francesco D M, Marco L, Alberto P. Overview of anti-islanding algorithms for PV systems. Part I: passive methods [C]. Proceedings of 12th International Conference on Power Electronics and Motion Control. Portoroz, Slovenia, 2007: 1878-1883.
[43]张纯江,郭忠南,孟慧英.主动电流扰动法在并网发电系统孤岛检测中的应用电工技术学报. 2007, 22(7): 176-179.
[44] T CY Wang, Z H Ye, G Sinha, X M Yuan. Output Filter Design for a Grid-interconnected Three-Phase Inverter[C]. IEEE Proceedings of IEEE PESC Conference, Acapulco, 2003, (2): 779~784.
[45] M Liserre, F Blaabjerg, S Hansen. Design and Control of an LCL-filter based Three-phase Active Rectifier. IEEE Trans. on Industry Applications, 2005, 17(1): 1281~1291.
[2]冯垛生,宋金莲,赵慧,等.太阳能发电原理与应用[M].北京:人民邮电出版社, 2007: 3-32.
[3]罗运俊,何梓年,王长贵.太阳能利用技术[M].北京:化学工业出版社. 2005: 12-23.
[4]陆晓楠,黄立培,杨仲庆.中国光伏发电产业的现状及发展趋势[J].高科技与产业化, 2009, (02): 42-43.
[5]施钰川.太阳能原理与技术[M].西安:西安交通大学出版社, 2008: 18-32
[6] The PV industry 2009: in search of stability and sustainability, Renewable Energy World, 2009.
[7]侯岩.全球光伏电池的生产趋势及市场分析[J].电源技术2011 (3): 338-339.
[8]沈辉,舒碧芬,闻立时.我国太阳能光伏产业的发展机遇与战略对策[J].电池, 2005, 35(6): 430-432.
[9]钱伯章太阳能技术与应用[M].北京:科学出版社2010: 1-10
[10] Luque A, Hegedus S. Handbook of Photovoltaic Science and Engineering[M]. UK, Wiley, 2003: 11-19.
[11]吴理博.光伏并网逆变系统综合控制策略研究及实现[D].清华大学电气工程, 2006: 17-21.
[12]李丽,张贵友,陈人杰,陈实,吴锋.太阳能电池及关键材料的研究进展[J]化工新型材料, 2008,(11): 21-23.
[13]蒋荣华,邓良平,冯地直,等.我国硅太阳能电池的新发展[J].新材料产业, 2008, (02): 39-46.
[14] IEEE Std 929-2000. IEEE Recommended Practice for Utility Interface of Photovoltaic (PV) Systems. NY, USA: IEEE, 2000.
[15] Cody G, Tiedje T.A learning curve approach to projecting cost and performance in thin film photovoltaic[C]. Photovoltaic Specialists Conference, Conference Record of the Twenty Fifth IEEE. Washington: IEEE, 1996: 1521-1524.
[16]陈维,沈辉,邓幼俊,舒杰.光伏发电系统中逆变器技术应用及展望[J].电力电子技术. 2006. (04): 130-133.
[17] Meinhardt M, Cramer G. Past, present and future of grid connected photovoltaic and hybrid power systems [C]. Proceedings of IEEE Power Engineering Society Summer Meeting, USA, 2000: 1283-1288.
[18]吴理博,赵争鸣,刘建政,等.具有无功补偿功能的单级式三相光伏并网系统[J].电工技术学报, 2006, 21(1): 28-32.
[19] Hussein K H, Muta I, Hoshino T, et al. Maximum photovoltaic power tracking: an algorithm for rapidly changing atmospheric conditions[J]. Generation, Transmission and Distribution, IEE Proceedings-, 1995, 142(1):59-64.
[20]曾光奇,胡均安,王东,等.模糊控制理论与工程应用[M].华中科技大学出版社. 2006: 18-21.
[21]韩峻峰,李玉惠.模糊控制技术[M].重庆大学出版社2003: 34-36.
[22] Tae-Yeop K, Ho-Gyun A, Seung Kyu P, et al. A novel maximum power point tracking control for photovoltaic power system under rapidly changing solar radiation[C]. IEEE International Symposium on Industrial Electronics, 2001. Proceedings. ISIE 2001. Pusan: IEEE, 2001: 1011-1014.
[23]张崇巍,张兴. PWM整流器及其控制[M].北京,机械工业出版社. 2005: 21-30.
[24] Hoffmann, Winfried. PV solar electricity: Market growth and perspective[J]. Solar Energy Meterials and Solar Cells, 2006, 90(18): 3285-3311.
[25]陈伯时.电力拖动自动控制系统——运动控制系统[M].机械工业出版社, 2003: 197-200.
[26] Marian P Kazmierkowski, Luigi Malesani. Current Control Techniques for Three-phase Voltage Source PWM Converter: A Survey[J]. IEEE Trans. on Industrial Electronics, 1998, 45(5): 691~703.
[27] DK Min, SC Ahn, DS Hyun. Control of A PWM Converter In Different Input Voltage Conditions[C]. Proceedings of IEEE IECON Conference, New Orleans, 1997: 882~887.
[28]顾和荣,杨子龙,邬伟扬.并网逆变器输出电流滞环跟踪控制技术研究[J].中国电机工程学报, 2006, (09): 108-112.
[29] Kang B J,Liaw C M.Robust hysteresis current-controlled PWM scheme with fixed switching frequency[J]. IEE Proceedings- Electric Power Applications,2001,148(6): 503-512.
[30] Q. Zeng, L. Chang, and P. Song, SVPWM-based current controller with grid harmonic compensation for three-phase grid-connected VSI[C], in Proc. IEEE 35th Annu. PESC, 2004: 2494–2500.
[31] Hyung-Tae Moon, Hyun-Soo Kim, Myung-Joong youn. A discrete-time predictive current control for PMSM [J]. IEEE Trans, Power Electronics, 2003, 18(1): 464-472.
[32] K Nishida, M Rukonuzzman, M Nakaoka. Advanced current controlimplementation with robust deadbeat algorithm for shunt single-phase voltage-source type active power filter[J]. IEE Proc, Electric Power Applications, 2004, 151(3): 283-288.
[33]李春龙,沈颂华,卢家林,等.具有延时补偿的数字控制在PWM整流器中的应用[J].中国电机工程学报. 2007 (7): 94-97.
[34] K Nishida, M Rukonuzzman, M Nakaoka. Advanced current control implementation with robust deadbeat algorithm for shunt single-phase voltage-source type active power filter[J]. IEE Proc. Electric Power Applications, 2004, 151(3): 283-288.
[35] J. L. Agorreta, L. Reinaldos, R. Gonzalez, M. Borrega, J. Balda, and L. Marroyo. Fuzzy switching technique applied to PWM boost converteroperating in mixed conduction mode for PV systems[J]. IEEE Trans, Ind. Electron, 2009 56(11): 4363–4373.
[36]周德佳,赵争鸣,吴理博.基于仿真模型的太阳能光伏电池阵列特性的分析[J].清华大学学报. 2007 47(7): 1109-1112.
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