三相光伏并网逆变器的研制及并网控制策略研究
摘要
随着当今社会能源和环境问题的日益突出,作为可再生能源的太阳能能源得到了广泛的研究和应用。为了充分发挥光伏发电的独特优势及提高其利用效率,大型光伏并网发电成为新能源领域的发展趋势。本文主要研究光伏电压型并网PWM逆变器的并网控制,光伏并网系统具有输出电流正弦化、功率因数可调、消除电网侧谐波分量,具备反孤岛检测等功能,输出电能质量符合分布式发电并网标准。
本文以实际项目为背景,设计并研制了基于DSP的三相电压型并网PWM逆变器,论文的主要工作如下：
首先,本文对三相电压型并网PWM逆变器主电路拓扑结构、工作原理进行了详细分析,建立三相电压型并网PWM逆变器在静止、旋转坐标系下的数学模型,为系统的并网控制策略设计奠定了基在此基础上建础。
第二,根据所建立的数学模型,详细分析了三相并网逆变器的并网控制策略,包括直接电压定向控制方法的理论分析及实现方法；空间矢量脉宽调制法的基本原理和实现流程；三相软件锁相环的原理分析及设计。结合实际系统参数设计通过Matlab/simulink仿真软件对并网控制方法进行仿真验证,通过仿真结果证明上述控制策略的可实现性。
第三,简要介绍了反孤岛检测技术的基本原理和检测标准,详细对比分析了各种被动式和主动式孤岛检测方法的基本原理及其适用范围,并通过软件仿真验证各主动式方法的有效性,通过仿真结果进行盲区分析,同时结合主动式孤岛检测方法提出一种组合式的主动式孤岛检测方法,本文给出了该方法的实现流程,并通过软件仿真验证该方法具有检测时间短、检测盲区小及对电能质量影响较小的特点。
第四,详细给出了DSP主控芯片、IGBT驱动电路、电压电流检测电路、锁相电路、保护电路、缓冲电路等硬件电路的设计,并根据主电路参数设计原则确定主电路中交流电抗器及电容器的取值。
第五,基于TI公司的开发软件CCS3.3对三相电压型PWM逆变器进行了软件设计,详细介绍并编写A/D采样程序、并网锁相程序、闭环PI控制程序、SVPWM程序、保护程序等。
最后,设计并研制了3kW的三相电压型并网PWM逆变器样机。通过软硬件调试得到较理想的实验结果,验证上述控制理论的有效性。
With the problem of energy and environment becoming looming large, the research and application of the solar, one kind of renewable energy, has aroused widespread concern. To give full play to the unique advantages of photovoltaic power generation and improve its efficiency, large scale photovoltaic grid power generation become the trend. This paper mainly studies grid-connected control of photovoltaic grid voltage source PWM inverter. Photovoltaic grid-connected system is featured by sinusoidal current output, adjusted power factor, Elimination of grid side harmonic component and the function of anti-islanding detection. The quality of power output is in compliance with standard of distributed grid-connected power generation.
This paper is based on actual project in which low power three-phase voltage type PWM inverter which based on DSP is designed and developed. The paper focuses on the following contents:
At the beginning, topology structure of Three-phase grid voltage type PWM inverter's main circuit and working principles are analyzed in detail and then, mathematical models of invert under both the static and rotating coordinate system are established which lay the foundation for design of grid-connected control.
Secondly, on the basis of the mathematical model, grid control strategy of three-phase grid inverter is deeply researched, including theoretical analysis of direct voltage control method, basic principle and process of SVPWM, principle analysis of three phases software phase-locked loop. Combined with the actual system parameters, grid-connected control method is stimulation verified by Matlab/simulink simulation software, to improve the realizability of the above theory.
Thirdly, this thesis described the mechanism of islanding phenomenon, the model and main research methods of anti-islanding protection. Classifying the popular anti-islanding techniques into two major categories:the passive and the active methods, advantage and restriction are presented respectively. Popular islanding detectiong methods are described in detail. Based on the MATLAB simulation envoronment, a number of issues about islanding protection are studid. This paper raised a new active islanding detection whichi combined active frequency drift and active current disturbance. This method has the following characteristics of short detection time, small NDZ, low impact on power quality verified by MATLAB based simulation and experiment.
Fourthly, the hardware design including the core control circuit, IGBT driver circuit, detection circuit, protection circuit, buffer circuit was elaborated. The range of AC reactor and capacitor were determined by the method of main circuit parameters design according to requirements of the control system.
Fifthly, the software design of three-phase voltage source PWM inverter which includes voltage and current A/D sampling procedures, SVPWM program, protection algorithm and double closed-loop PI control strategy was carried out based on CCS3.3.
Finally, a3kW three-phase voltage source PWM inverter prototype was accomplished. The effectiveness of the control theory was verified by hardware and software debugging and got better experimental results.
本文以实际项目为背景,设计并研制了基于DSP的三相电压型并网PWM逆变器,论文的主要工作如下：
首先,本文对三相电压型并网PWM逆变器主电路拓扑结构、工作原理进行了详细分析,建立三相电压型并网PWM逆变器在静止、旋转坐标系下的数学模型,为系统的并网控制策略设计奠定了基在此基础上建础。
第二,根据所建立的数学模型,详细分析了三相并网逆变器的并网控制策略,包括直接电压定向控制方法的理论分析及实现方法；空间矢量脉宽调制法的基本原理和实现流程；三相软件锁相环的原理分析及设计。结合实际系统参数设计通过Matlab/simulink仿真软件对并网控制方法进行仿真验证,通过仿真结果证明上述控制策略的可实现性。
第三,简要介绍了反孤岛检测技术的基本原理和检测标准,详细对比分析了各种被动式和主动式孤岛检测方法的基本原理及其适用范围,并通过软件仿真验证各主动式方法的有效性,通过仿真结果进行盲区分析,同时结合主动式孤岛检测方法提出一种组合式的主动式孤岛检测方法,本文给出了该方法的实现流程,并通过软件仿真验证该方法具有检测时间短、检测盲区小及对电能质量影响较小的特点。
第四,详细给出了DSP主控芯片、IGBT驱动电路、电压电流检测电路、锁相电路、保护电路、缓冲电路等硬件电路的设计,并根据主电路参数设计原则确定主电路中交流电抗器及电容器的取值。
第五,基于TI公司的开发软件CCS3.3对三相电压型PWM逆变器进行了软件设计,详细介绍并编写A/D采样程序、并网锁相程序、闭环PI控制程序、SVPWM程序、保护程序等。
最后,设计并研制了3kW的三相电压型并网PWM逆变器样机。通过软硬件调试得到较理想的实验结果,验证上述控制理论的有效性。
With the problem of energy and environment becoming looming large, the research and application of the solar, one kind of renewable energy, has aroused widespread concern. To give full play to the unique advantages of photovoltaic power generation and improve its efficiency, large scale photovoltaic grid power generation become the trend. This paper mainly studies grid-connected control of photovoltaic grid voltage source PWM inverter. Photovoltaic grid-connected system is featured by sinusoidal current output, adjusted power factor, Elimination of grid side harmonic component and the function of anti-islanding detection. The quality of power output is in compliance with standard of distributed grid-connected power generation.
This paper is based on actual project in which low power three-phase voltage type PWM inverter which based on DSP is designed and developed. The paper focuses on the following contents:
At the beginning, topology structure of Three-phase grid voltage type PWM inverter's main circuit and working principles are analyzed in detail and then, mathematical models of invert under both the static and rotating coordinate system are established which lay the foundation for design of grid-connected control.
Secondly, on the basis of the mathematical model, grid control strategy of three-phase grid inverter is deeply researched, including theoretical analysis of direct voltage control method, basic principle and process of SVPWM, principle analysis of three phases software phase-locked loop. Combined with the actual system parameters, grid-connected control method is stimulation verified by Matlab/simulink simulation software, to improve the realizability of the above theory.
Thirdly, this thesis described the mechanism of islanding phenomenon, the model and main research methods of anti-islanding protection. Classifying the popular anti-islanding techniques into two major categories:the passive and the active methods, advantage and restriction are presented respectively. Popular islanding detectiong methods are described in detail. Based on the MATLAB simulation envoronment, a number of issues about islanding protection are studid. This paper raised a new active islanding detection whichi combined active frequency drift and active current disturbance. This method has the following characteristics of short detection time, small NDZ, low impact on power quality verified by MATLAB based simulation and experiment.
Fourthly, the hardware design including the core control circuit, IGBT driver circuit, detection circuit, protection circuit, buffer circuit was elaborated. The range of AC reactor and capacitor were determined by the method of main circuit parameters design according to requirements of the control system.
Fifthly, the software design of three-phase voltage source PWM inverter which includes voltage and current A/D sampling procedures, SVPWM program, protection algorithm and double closed-loop PI control strategy was carried out based on CCS3.3.
Finally, a3kW three-phase voltage source PWM inverter prototype was accomplished. The effectiveness of the control theory was verified by hardware and software debugging and got better experimental results.
引文
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[8]刘飞.三相并网光伏发电系统的运行控制策略[D].[博士学位论文].2008
[9]Testing Procedure of Islanding Prevention Measures for Grid-Connected Photovoltaic Power Generation Systems; International Standard IEC 62116; WG6 Draft; International Electro technical Commission,2003.
[10]龚锦霞,解大,张延迟.三相数字锁相环的原理及性能[J].电工技术学报,2009,24(10)：94-99.
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[25]FukudaS, YodaT. A Novel Current tracking Method for Active Filters Based on a Sinusoidal Internal Model[J]. IEEE Trans Ind Appl,2001. 37(3):888-895.
[26]蒋燕君,张超,何湘宁.基于DSP的光伏并网发电系统数字锁相技术[J].电源技术应用,2007,29-32.
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[28]Y. F. Wang, Y. W. Li. Grid synchronization PLL based on cascaded delayed signal cancellation[J]. IEEE Trans. Power Electron.,2011.
[29]J. Svensson, M. Bongiorno, A. Sannino. Practical implementation of delayed signal cancellation method for phase-sequence separation[J]. IEEE Trans. Power Del., vol.22, no.1, pp.18-26, Jan.2007.
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[31]J.M. Carrasco, J.T. Bialasiewicz, R.C.P Guisado. Power-Electronic Systems for the Grid Integration of Renewable Energy Sources:a survey[J]. IEEE Trans Industrial Electronics,2006,53(8):1009-1012.
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[2]赵晶,赵争鸣,周德佳.太阳能光伏发电技术现状及其发展[J].电气应用,2007,26(10).
[3]Mike Meinhardt, Gunter Cramer. Past Present and Future of grid connected Photovoltaic- and Hybrid-Power Systems[J]. IEEE,2000: 1283-1288.
[4]朱伟钢,林燕梅,周蕾.太阳能光伏发电在中国的应用[J].现代电力,2007,24(5).
[5]IEEE Standard for Interconnecting Distributed Resources with Electric Power Systems. IEEE Std.1547-2003; Institute of Electrical and Electronics Engineers,2003.
[6]光伏系统并网技术要求.中华人民共和国国家标准GB/T 19939-2005.
[7]王斯成.我国光伏发电有关问题研究[J].中国能源,2007,29(2).
[8]刘飞.三相并网光伏发电系统的运行控制策略[D].[博士学位论文].2008
[9]Testing Procedure of Islanding Prevention Measures for Grid-Connected Photovoltaic Power Generation Systems; International Standard IEC 62116; WG6 Draft; International Electro technical Commission,2003.
[10]龚锦霞,解大,张延迟.三相数字锁相环的原理及性能[J].电工技术学报,2009,24(10)：94-99.
[11]王兆安,黄俊.电力电子技术[M].第四版.北京：机械工业出版社[M].2004,2-6
[12]林渭勋.现代电力电子电路[M].浙江人学出版社,2002.
[13]张崇魏,张兴.PWM整流器及其控制[M].北京.机械工业出版社.2005.
[14]叶斌.电力电子应用技术[M].北京.清华大学出版社.2006.
[15]邓卫华,张波,丘东元,卢至峰,胡宗波.三相电压型PWM整流器 状态反馈精确线性化解耦控制研究[J].中国电机工程学报,2005,25(7)；97-103
[16]杨德刚,刘润生,赵良炳.三相高功率因数的电流控制[J].电工技术学报,2000(2)：83-87
[17]张兴,张崇魏.PWM可逆变流器空间矢量控制技术的研究[J].中国电机工程,2001(10)：102-105
[18]王毅,陈希有,徐殿国.空间矢量调制变换器闭环控制的研究[J].中国电机工程学报,2003,23(6)：164-169.
[19]刘正亮,谢门喜.空间矢量调制PWM算法研究[J].齐齐哈尔大学学报,2008.
[20]李峰.矢量控制系统中优化PWM控制策略的研究[D].天津：天津大学自动化学院,2004
[21]田亚飞,何继爱.电压空间矢量脉宽调制(?)(SVPWM)算法仿真实现及分析[J].Proceedingof the EPSA,2004, (8).
[22]田晓宇,吴延华.基于DSP的SVPWM矢量控制系统的研究[J].电气开关,2008,46(3)：40-43.
[23]Q. zeng, L. Chang. SVPWM—basedCurrent Controller with Grid Harmonic Compensation for Three-phase Grid connectedVSI[J].35th Annual IEEE Power Electronics Conference,2004.
[24]BJOKIE B, SO E. Phase measurement of distorted periodic signals based on nonsynchmnous digital filtering[J]. IEEE Trans on Instrum Meas,2001,50(4):864-867.
[25]FukudaS, YodaT. A Novel Current tracking Method for Active Filters Based on a Sinusoidal Internal Model[J]. IEEE Trans Ind Appl,2001. 37(3):888-895.
[26]蒋燕君,张超,何湘宁.基于DSP的光伏并网发电系统数字锁相技术[J].电源技术应用,2007,29-32.
[27]郑翔骥,陈道炼.基于软件锁相技术的光伏并网系统基准正弦电路[J].电力自动化设备,2009,29(6)：102-105.
[28]Y. F. Wang, Y. W. Li. Grid synchronization PLL based on cascaded delayed signal cancellation[J]. IEEE Trans. Power Electron.,2011.
[29]J. Svensson, M. Bongiorno, A. Sannino. Practical implementation of delayed signal cancellation method for phase-sequence separation[J]. IEEE Trans. Power Del., vol.22, no.1, pp.18-26, Jan.2007.
[30]IEEE Recommended Practice for Utility Interface of Photovoltaic (PV) Systems:IEEE Std 929-2000; Institute of Electri cal and Electronics Engineers,2000.
[31]J.M. Carrasco, J.T. Bialasiewicz, R.C.P Guisado. Power-Electronic Systems for the Grid Integration of Renewable Energy Sources:a survey[J]. IEEE Trans Industrial Electronics,2006,53(8):1009-1012.
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