【作者】 王磊；

【导师】 何玉林；

【作者基本信息】 重庆大学 ， 机械工程， 2011， 博士

【摘要】 随着风力发电产业快速的发展,欧美等国海上风力发电技术已日趋成熟,而我国海上风能的开发刚刚起步。为降低海上发电成本,需要风力发电机组的尺寸和复杂度不断的增加,对我国风力发电机组系统设计水平和制造能力提出了更新、更高的要求。正确地建立大型海上风力发电机组的系统动力学模型并通过仿真分析风力发电机组的性能及运动规律是海上风力发电机组系统设计的一个重要内容。对提高我国海上风力发电机组系统设计水平和制造能力,具有重要意义。在国家科技支撑计划项目“5.0MW近海风电机组研制及风能核心技术研究(项目编号:2009BAA22B02)”的资助下,将其子项目“海上风电机组系统动力学建模及仿真分析”的作为研究课题。在综合国内外相关研究的基础上,建立了包括近海风力发电机组风场、风轮气动力、流体动力学、结构动力学和控制模型的多场耦合风力发电机组系统动力学模型。论文完成的主要研究工作有:第一章中回顾了海上风力发电的历史发展,分析了现代海上风力发电技术发展的特点,综述了国内外海上风力发电机组风场建模、空气动力学、结构动力学及整机系统动力学建模与仿真的研究现状,从而提出了海上风力发电机组说明了系统动力学仿真分析的研究,给出了论文的主要研究内容,创新点和技术路线。第二章研究了海上风场的变化规律,针对于目前广泛使用的Von.karman随机功率谱的不足,分别采用修正Von.karman和Mann随机功率谱表示风速随时间的随机变化,建立不同点的风速互相关函数,通过逆Fourier变换得到风轮叶片上随时间变化风速时间历程。分别给出了叶素动量理论模型、固定尾迹模型以及自由尾迹模型三种空气动力学模型。在Matlab/Simulink下建模,并结合得到湍流风速时间历程,对某2MW海上风力机风轮进行气动分析,为风力发电机组系统动力学模型和空气动力学模型打下基础。第三章分别研究了规则波浪理论和不规则波浪理论。对Morison方程在工程上的适用范围进行更好的确定,应用Morison方程对海上风力发电机桩基础的波流力进行计算,并对流场作用于塔筒上的水动力的变化开展了研究。第四章在基于变速变桨主控策略基础上,针对变速变桨风力发电机组如何抑制传动链的扭转振动和塔架前后、侧向运动。动态入流以及估计风速,增加了载荷控制环、动态入流控制环以及估计风速前馈控制环,通过时域和频域分析与对比,说明增加的辅助控制环不但有利于降低载荷,减少超调量,同时也提高了控制系统的稳定性。第五章建立了基于Kane方法的作大范围运动海上风力发电机组系统的结构动力学模型,并使用假设模态离散化方法对其进行柔性化。将该模型与风场、气动力模型、波浪力模型一起,组成了海上风电机组气-弹-流相互耦合系统动力学模型。以变速变桨控制5MW海上风力发电机组为例,计算了在考虑线性波和非线性波情况与稳态风场和Mann湍流风场下的风力发电机组叶片和塔架的受力和变形情况。第六章通过建立浮式平台水动力学模型和锚泊系统动力学模型,并将耦合的水动力载荷与气动载荷加载到该漂浮式风电机组多柔体动力学的模型上,在ADAMS环境下进行风力机结构动态仿真分析。以某NREL5MW基本型数据,对漂浮式风电机组系统动力学模型进行仿真,并对发电机输出功率,叶尖在风轮面内与面外的位移以及浮式平台的摇荡位移进行分析。最后,在第七章总结了全文主要内容与成果,并展望了今后的研究工作。更多还原

【Abstract】 With the rapid development of offshore wind energy, the technology of Europe and U.S. for offshore wind turbine design was matured, and Chinese offshore wind energy development has just started. In order to reduce cost of offshore wind power, it is necessary to the increase of size and complexity of homemade offshore wind turbine. Also it has requested the improvement in wind turbine systematic design technology and manufacturing capacity. A reasonable systematic dynamic model and analysis of performance and dynamic load are important parts for systematic design of MW-class offshore wind turbine. Due to harsh marine environment of offshore wind turbine operation, the performance and extreme load will be impacted greatly. Therefore, a study of dynamics of offshore wind turbine has an important significance for development of offshore wind turbine systematic design and manufacturing capacity.The dissertation proposes a study entitled "Study on Systematic Dynamics and Simulation Analysis for offshore Wind Turbine", sponsored by National Support Science and Technology Project "5.0MW offshore wind turbine development and core technology research" (project number: 2009BAA22B02). Based on preliminary studies of foreign and domestic technology, offshore wind turbine systematic dynamic model include wind field model, rotor aerodynamic model, hydrodynamic model, structural dynamic model and advanced control model. In the dissertation, the major work and tasks are summarized as follows:In chapter 1, the historical development of offshore wind power generation is reviewed, and the modern development features of technology for offshore wind turbine is analyzed, and offshore wind farm, aerodynamics, hydrodynamics, structural dynamics and whole turbine systematic dynamics of modeling and simulation for foreign and domestic research on offshore wind turbine is summarized. The main research contents——systematic simulation and analysis of multi-field coupled model for offshore wind turbine and innovation and technology roadmap are discussed.In chapter 2, the variation pattern of offshore wind farm for offshore wind turbine is studied.the original BEM theory for wind turbine’s rotor was introduced and was modified to take the tip loss correction, yaw error correction and blade azimuth into consideration. The modified BEM model was set up in Simulink. Using the model, the inflow factor, the tangential factor of blade, rotor’s torque and output power was calculated. The Simulink model has taken more correction factors into consideration, and can simulate aerodynamics more correctly; besides, the model is easy to understand and to expand. Comparison between the results and Blade’s showed that the model was credible.The chapter 3, the theory of regular and irregular wave is described. The scope which Morison equation was used in project was better determined, and the wave force for the foundation of offshore wind turbine was calculated with Morison equation. In this chapter, the vibration of water dynamic when flow field acted on the tower was also studied.In chapter 4,For the requirements of drive train torsional vibration suppression of variable speed variable pitch wind turbine, the for-after and side-side vibration suppression of tower and the speed of dynamic response, the model of load control loop, GDW control loop and estimated wind speed feed forward control loop which were added to the main controller were created based on the variable speed variable pitch control strategy in the fourth chapter.In chapter 5, the structural dynamics model of offshore wind turbine which was flexible with the assumed mode discrimination method was established based on Kane method. The model includes the wind field, aerodynamic model, wave force model, form an aero-elasticity-flow coupling system dynamics model of offshore wind turbine. With variable speed variable pitch 5MW offshore wind turbine, for example, the force and deformation situation of wind turbine blade and tower was calculated taking into account linear and nonlinear wave and steady-state wind conditions and Mann turbulent wind field.In chapter 6, Dynamics of deep-sea floating wind turbine was analyzed by the computer simulation technology. Firstly the wave dynamics model of floating platform was established. Secondly the force was loaded on the multi-flexible body dynamics mode.And then the whole model and results were turned into ADAMS model. Taking a 5MW wind turbine for example, floating wind turbine system was the analyzed by multi-field coupling dynamic model. The results show that: during operation of the floating wind turbine, its floating platform must withstand great hydrodynamic force, and the dynamic response of whole structure and fluctuation of power are great impacted by the coupling of aerodynamic and hydrodynamic loads. In Chapter 7, the important results and conclusions of the dissertion are summarized the prospect of the research is opened up.更多还原