外文翻译--变速恒频交流励磁双馈风力发电系统及其控制技术研究.doc

中文中文 17651765 字字 毕 业 设 计 外 文 文 献 译 文 及 原 文 学学 生：生： 学学 号：号： 院院 （系）：（系）： 电气与信息工程学院电气与信息工程学院 专专 业：业： 电气工程及其自动化电气工程及其自动化 指导教师：指导教师： 20092009 年年 6 6 月月 1010 日日 变速恒频交流励磁双馈风力发电系统及其控制技术研究 R. Pen , J . C.Clare , G. M.Asher 摘要：随着电力电子器件制造及其应用技术的飞速发展，使得大型变速恒频风电机组成为风电机组 主要的技术发展方向之一，而能柔性连接风电机组及电力系统的变速恒频双馈风电机组已成为目前 风电开发的主流机型。因此，有关该风电机组的技术、运行特性、并网后系统的安全与稳定等问题 的研究也相应成为风电领域的重要研究方向。在分析了现有风力发电机并网技术的基础上，讨论了 交流励磁变速恒频异步双馈风力发电机的并网控制，建立了基于磁场定向矢量控制、不受转速变化 影响的空载，负载和孤岛并网三种并网控制方案。 关键词：变速恒频，风力发电，双馈，并网运行 近年电力电子器件制造及其应用技术的飞速发展，使得大型变速恒频风电机组成为风电机组主 要的技术发展方向之一，而能柔性连接风电机组及电力系统的变速恒频双馈风电机组已成为目前风 电开发的主流机型。因此，有关该风电机组的技术、运行特性、并网后系统的安全与稳定等问题的 研究也相应成为风电领域的重要研究方向。为开发我国风电领域的新技术，国家高技术研究发展计 划(863)中资助了兆瓦级变速恒频风电机组项目。本文结合该项目子课题兆瓦级变速恒频风电 机组并网技术研究的部分内容，在广泛分析国内外有关资料的基础上，研究了大型变速恒频双馈 风力发电机组的动态建模、运行特性、以及风电机群并网后电压一无功控制策略，其主要研究内容 和创新性的成果如下： 第一、推导了形式简单、能正确反映运行特性、且易于数值仿真实现的双馈感应发电机简化三 阶动态数学模型。相应于控制变量发生阶跃和渐变，对双馈感应发电机精确模型和该简化模型的响 应特性进行了详细比较，比较结果充分表明了该简化模型具有良好的精确度，能很好的代替精确模 型应用在转子转速变化范围较大，发电机功率因数较高的双馈感应发电机的建模和研究中。因此， 该模型能较好地应用于变速恒频双馈风电系统的研究。 第二、以双馈感应发电机三阶简化动态数学模型为基础，推导了适用于小干扰稳定分析的线性 化模型和相应系统的闭环传递函数和开环传递函数，并首次应用开环传递函数和根轨迹方法，分析 了双馈感应发电机初始运行点与系统动态品质的关系。 第三、首次提出了由整流和逆变部分的调制比和相位差四个控制参数表征的用于双馈机组的变 频器数学模型，并依据变速恒频双馈风力发电机组组成构件的物理特性，建立了能表征变速恒频风 电机组特性的整体动态数学模型。同时，基于 MATLAB 平台创新性地开发了变速恒频双馈风电机 组并网特性研究的仿真程序。 第四、分析了变速恒频双馈风电机组的运行特性。在稳态特性方面，分析了变速恒频双馈风力 发电机组的有功功率特性、无功功率特性和 P-Q 容量极限。在动态特性方面，对变速恒频双馈风电 机组和常规变桨距恒速风电机组的动态特性作了对比仿真，仿真结果说明了前者优越的运行特性。 此外，以直接接入大电网的变速恒频双馈风电机组为例，对不同风况下风电机组的运行特性进行了 仿真。仿真的结果说明了变速恒频双馈风力发电系统动态模型的正确性和控制目标设计的合理性， 表明了变速恒频双馈风电机组所具备的无功一一电压调节潜力。 第五、分析了变速恒频双馈风电机组的运行区域，确定了理想工况下总控制目标，首次提出了 定子磁场旋转坐标系下的变频器功率一一电压控制策略，并设计了变速恒频双馈风电机组的整体控 制器。 第六、创新性地提出了变速恒频双馈风电机群并网的分段分层实时优化运行控制策略。该策略 按风速分段、并按控制单元中控制参考值的整定和对控制参考值的追踪分层。以达到在保证风电机 组安全稳定运行的同时，最大效率的利用风能和参与全网无功优化运行，提高系统电压稳定性的目 标。并以我国北方某风电场为例，仿真分析了该控制策略下，风速发生扰动变化和系统侧发生故障 时，单台变速恒频风电机组运行特性及风电机群与接入系统中关键节点的电压特性。仿真结果表明， 本文提出的分层分段控制策略不仅能保证风电机组最大效率的利用风能，还能充分发挥机组的无功 调节能力，从而平衡扰动，提高风电机群和接入系统的电压稳定性，保证整个系统的优化运行。 综上所述，本文从国内外对双馈感应发电机的研究现状出发，对变速恒频双馈风电机组的动态 建模及运行特性进行了全面分析，完成了变速恒频双馈风电机群并网运行控制策略的设计和相应软 件的开发，从而构成了“大型变速恒频风电机组并网技术研究”中控制策略方面的一个完整的思路 与分析软件平台。 参考文献 1 F. Giraud and Z. M. Salameh, “ Wind-driven variable-speed, variable frequency, double-output, induction generators,” Electric Mach. Power Syst. , vol. 26, pp. 287-297, 1998. 2 M. N. Eskander and M. T. El-Hagry, “Optimal performance of double output induction generator used in WECS,”Electric Mach. Power Syst.,vol. 25, pp. 1035-1046, 1997. 3 E. Akpinar and P. Pillay, “Modeling and performance of slip energy recovery induction motor drives,”IEEE Trans. Energy Conversion, vol. 5, pp. 203-210, Mar. 1990. 4E. Akpinar and P. Pillay, “A computer program to predict he performance of slip energy recovery induction motor drives,”IEEE Trans. Energy Conversion , vol. 5, pp. 357-365, June 1990. 5J. B. Ekanayake, L. Holdsworth, X. Wu, N. Jenkins,“Dynamic Modelling of Doubly Fed Induction Generator Wind Turbines”,IEEE Trans. On power systems ,VOL.18, No .2,May 2003,pp.803-809. 6 L. Refoufi, B. A. T. Alzahawi, A. G. Jack, “(R)Analysis and modeling of the steady state behavior of the static Kramer induction generator,”IEEE Trans. On Energy Conversion , Vol. 14, No. 3, September 1999, pp. 333-339. Research on VSCF AC Excitation Doubly fed Wind Energy Generation System and Its Control Technology R. Pen , J . C.Clare , G. M.Asher ABSTRACT:with the great development in manufacture of power electronic converter and its application technology，the variable speed wind turbine(VSWT)with large capacity has become one primary technology directions of wind turbinesThe VSWT with doublyfed induction generator(DFIG)which can flexibly join wind turbineto power system has turned into mainstream machine in the field of exploring wind energy in the world nowIt is therefore important to study the technology，operation characteristics，safety and stability in an electric power system with this type wind turbinesThe use of wind energy for electricity generation as a mature technology of renewable energy use patterns have developed rapidly.VSCF AC excited DFIG system and its grid-connected control technology is studied in this paper. KEYWORDS:VSCF,wind power generation,doubly fed,grid-connected In recent years，with the great development in manufacture of power electronic converter and its application technology，the variable speed wind turbine(VSWT)with large capacity has become one primary technology directions of wind turbinesThe VSWT with doublyfed induction generator(DFIG) which can flexibly join wind turbineto power system has turned into mainstream machine in the field of exploring wind energy in the world nowIt is therefore important to study the technology，operation characteristics，safety and stability in an electric power system with this type windturbinesIn order to explore the new technology of wind power in our country，a project named“The VSWT with large capacity of MW level”has been supported by National High Technology Research and Development Plan(863 plan)In this dissertation，the dynamic modeling，operation characteristics of VWST with doubly-fed generator and voltagereactive power control strategy of a wind farm in an electric power system are studied based on the subproject that is entitled as research on operation technology of VSWT with large capacity in an electrical power system and the full analysis on the references from domestic and aboardThe primary contents and original contributions of this dissertation are as follows： Firstly，a simply 3rd order dynamic model for DFIG is developedThe proposed model is adequate to describe dynamic behaviors and is easy to simulate by computerSince control variables have taken place step changes and gradual changes，a detailed comparison of dynamic behaviors is made between the proposed model and exact model in the dissertationThe results are shown that the proposed model has a favorable definition and can substitute the exact model in research on DFIG with high power factor and large range of rotor speedTherefore，the 3rd model could be applied in study on VSWT with DFIG. Secondly，based on 3rd order dynamic model of DFIG，a linear model in state space formulation and transfer functions fitting for analysis on small disturbance stability of DFIG are presentedMoreover using open transfer function and eigenvalue locus for the first time，the relationship between original operation point and dynamic characteristics are discussed in the dissertation. Thirdly，a model of frequency converter that is expressed by four control parameters，that is，modulation ratio and phase difference of converter and inverter is originally presented in this dissertation Meanwhile，a aggregated dynamic model of VSWT is established based on the physical characteristics of composing components Then a simulation tool of VSWT is originally developed by using MATLAB Fourthly，the operation characteristics of VSWT are discussed in this dissertationAt the aspects of steady characteristics，the active power，reactive power and P-Q capacity limit are analyzedAt the aspects of dynamic characteristics，the dynamic behaviours are simulated contrastively between VWST and constant speed wind turbine (CSWT)The results show that VSWT has more superior behaviorsFurthermore，taking the example of VS WT with DFIG connected straight with large gridthe operation characteristics are simulated under the different types of windIt is shown that the proposed model in this dissertation is correct，the design of control objects is rational and it is also indicated that VSWT has a potential to regulate reactive power and voltage Fifthlythe operation areas of the VSWT with DFIG are analyzed and the general control objects in the ideal situation are made certain in this dissertationMoreover，a powervoltage control strategy of frequency converter at the coordinate system of rotating stator magnetic field is originally developed and the general controller is designed in the dissertation Sixthlya real optimized operation control strategy of VSWT operation with grid is presented ori ginally in this dissertation.The control strategy is divided into two subsections according to wind speed，and two layers according the amending control references and tracing control referencesIts aims are to ensure safe operation Simultaneous，it can improve operation efficiency of VSWT,take part in the reactive power optimization of the grid and enhance the voltage stability of power systemsThen taking the example of a wind park lied in north of china，the operation characteristics of single VSWT and voltage characteristics of grid are simulated and analyzed when some disturbances about wind speed emerge and some faults in the systems take place under the control strategyThe results show that the proposed control strategy not only can carry out optimal operation of VSWT but also adequately exert the regulation ability of reactive power of DFIG and so disturbances are balanced and the voltage stability of grid is availably improved，optimal operation of the electric power system is reached In summary，based on the research status of DFIG at home and aboard，the dynamic modeling and operation characteristics of VSWT are fully analyzed in this dissertationThen the control strategy of VSWTs in the power systems is accomplished and a simulation tool is developed by using MATLAB correspondinglyThereby，the work makes up of a integrated research at aspect of control strategy about “Operation technology of VSWT with large capacity in the grid“ References 1 F. Giraud and Z. M. Salameh, “ Wind-driven