风场风况是影响风力机气动和结构特性的直接因素,进而影响功率输出、稳定性和控制策略。在三维风场建模的基础上,对5种不同风况下的风速及相干湍流风的时域变化进行了模拟。结合气动计算结果对各风况下的叶尖挥舞和摆振位移,叶根挥舞、摆振、变浆力矩进行了动力学响应仿真,得到其各自的动态响应。控制策略采用变桨、变风速控制,极限风况下采用定时顺桨控制。结果发现克赫波更适合极限风况的仿真,并且通过添加相干湍流到基础湍流上能模拟拟序结构。同时,研究表明相较于参考风速为额定风速,在切出风速下,叶尖位移同时体现为挥舞和摆振,且变化频率、剧烈程度都增加;叶根载荷中挥舞弯矩均值较小,但在短时间内波动跨度大,是风力机叶片产生疲劳的主要载荷。

ABSTRACT:The wind directly decides the aerodynamic and structural characteristics of wind turbine, which affect the power output, the stability and control strategy. On the basis of modeling full field wind, this paper simulated five different wind fields with different speed or turbulence intensity. Combined with the aerodynamic results, it simulated the dynamic response of the out-of-plane, in-plane tip deflections; out-of-plane, in-plane, pitching moments at the blade root. Variable speed & pitch were used as the wind turbine control strategy at the rated wind speed events. Under the wind of extreme turbulence, the control strategy was normal pitch-to-feather. The results show that the Kelvin-Helmholtz billow is more suitable for turbulence wind simulation. It can simulate coherent structure by adding a coherent turbulence wind on the background wind. At the same time, the study shows that the reference wind speed is the rated speed, the cut-out wind speed simulations have

本文提出一种确定风电机组叶片载荷量与传感器输出电信号之间关系的标定方法，消除摆振与挥舞弯矩之间的正交敏感，以获得更为真实的载荷数据。主要讨论了如何利用叶片自身重量进行载荷标定的过程，并利用标定矩阵确定正交敏感度，从而校正测量结果的相关问题。阐述了叶片摆振和挥舞方向的载荷标定方法，介绍了正交敏感度的产生与影响，将标定矩阵引入到叶片载荷标定中。根据实测的叶片载荷标定数据，分析了影响因素并校正了测量结果，提高了载荷测量结果的准确性、可靠性。

Te calibration method for determining wind turbine blade loads and output signals were introduced. Cross-sensitivity between edgewise and fatwise signal measurements was eliminated so as to get more actual load data.Tis paper mainly discussed how to use the blade''s own weight for calibration and made sure cross-sensitivity between edgewise and flatwise signal measurements by calibration matrix, then correct the measurements. Te calibration method of two measurement signals on the edgewise and flatwise bending moments was expounded. The production and effect of cross-sensitivity were introduced and the calibration matrix was used in the blade load calibration in this paper. Te infuencing factors were summarized and the measurement results were corrected according to the calibration data of blade loading test so as to ensure the accuracy and the reliability of the results.

颤振对风力机叶片有巨大破坏力,作为一种典型的气动弹性稳定性问题,在现代风力机的叶片设计中越来越受到重视。建立叶片三维叶型模型和整机振动结构模型,利用振型叠加法计算不同振动模态下的特征频率、阻尼比和振型,得出不同叶片结构参数与颤振的关系。结果表明,叶片型面质心和扭转中心的距离、拍打方向弯曲刚度和挥舞方向弯曲刚度对颤振发生有较大影响。

Flutter has an enormous destructive power to wind turbine blades. As a typical dynamic aeroelastic stability problem, people are paying more and more attentions to the flutter in the design of the blades. This article established a three-dimensional model for a blade and a vibration structural model for the entire wind turbine. Using the modal superposition method, the natural frequencies, damping ratios and mode-shapes of different vibration modes of the blade were computed. The affect of the structural parameters of the blade on the flutter was obtained. Results show that, the distance from mass center to torsion center, flapwise bending stiffness and edgewise bending stiffness have great impact on the flutter.

以大功率风力发电机组为研究对象,采用线性叶素动量理论将叶片拍打方向的相对风速变化转换为叶片所受的力和力矩(叶根拍打方向和挥舞方向的力矩)的变化。通过Coleman变换进行转换,建立系统状态空间方程。对其进行独立变桨控制设计理论研究,采用MATLAB/SIMULINK实现控制器的编程,分析结果与统一变桨比较表明:独立变桨距控制比统一变桨距控制具有更好的减载效果,更适合大型风力发电机组。通过独立变桨,可以降低风力发电机的载荷,减少维护费用,延长风机的使用寿命。

A thorough study on large-scale wind turbine is presented ,and the force and torque(flap wise and edge wise ) are derived from wind inflow velocity based on BEM theory . Through the Coleman transformation ,a system state space equation is established .Based on the equation ,the theory research on individual pitch control is studied and programmed in MATLAB/SIMULINK .The theory research and engineering application show the superiority of individual pitch control design on load reduction ,w hich is more suitable for the control of large-scale wind turbine .Individual pitch control can reduce the load that is happened in the operation process ,so as to extend system service life and decrease maintenance .

针对大型风力机叶片气弹振动问题,提出一种基于脉冲响应的大型风力机柔性叶片结构阻尼有效分析方法.采用一种5自由度的超级单元,将柔性叶片离散成由若干超级单元构成的多体系统,基于计算多体系统动力学中的R-W方法建立了叶片的动力响应模型.以美国可再生能源实验室(NREL)发布的5 MW近海风力机叶片为研究对象,通过分析叶片在脉冲激励下的动力学响应得到其传递函数,由半功率带宽法计算叶片在静止和运转工况下的挥舞与摆振结构阻尼,从而为确定叶片气弹稳定性的边界提供依据.该研究对于指导叶片结构与气动外形设计、帮助确定其气弹稳定性边界具有重要意义.

In order to solve the aeroelastic vibration problem of large wind turbine blade,an effective analytical method for the structural damping of flexible blade of large wind turbine based on pulse response was proposed.A kind of super units with 5 degrees of freedom (DOFs)was used to discretize the flexible blade into a multi-body system (MBS)which consists of several super units,and the dynamic response model for the blade was established based on the R-W method in computing the multi-body system dynamics.The 5MW offshore wind turbine blade issued by the United States Renewable Energy Laboratory (NREL)was chosen as the research subject,and the transfer function of blade was obtained by analyzing the dynamic response of blade under the action of pulse excitation.In addition,the structural damping of blade in both flapwise and edgewise modes under the static and rotating conditions was calculated by the half-power bandwidth method in order to provide a foundation for confirming th