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1.
Active load reduction strategies such as individual pitch control (IPC) and trailing edge flap (TEF) actuation present ways of reducing the fatigue loads on the blades of wind turbines. This may enable development of lighter blades, improving the performance, cost effectiveness and viability of future multi‐megawatt turbine designs. Previous investigations into the use of IPC and TEFs have been limited to turbines with ratings up to 5 MW and typically investigate the use of these load reduction strategies on a single turbine only. This paper extends the design, implementation and analysis of individual pitch and TEFs to a range of classically scaled turbines between 5 and 20 MW. In order to avoid designing controllers which favour a particular scale, identical scale‐invariant system identification and controller design processes are applied to each of the turbines studied. Gain‐scheduled optimal output feedback controllers are designed using identified models to target blade root load fluctuations at the first and second multiples of the rotational frequency using IPC and TEFs respectively. The use of IPC and TEFs is shown in simulations to provide significant reductions in fatigue loads at the blade root. Fatigue loads on non‐rotating components such as the yaw bearing and tower root (yaw moment) are also reduced with the use of TEFs. Individual pitch performance is seen to be slightly lower on larger turbines, potentially due to a combination of reduced actuator bandwidth and movement of the rotational frequency of larger turbines into a more energetic part of the turbulent spectrum. However, TEF performance is consistent irrespective of scale. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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A novel control concept for fatigue load reduction with trailing edge flaps based on the measurement of the inflow locally on the blade was presented. The investigation was conducted with the aeroelastic code HAWC2. The aerodynamic modelling in the code is based on blade element momentum theory. The simulations were carried out for the NREL 5MW reference wind turbine, and the mean wind speed at hub height was 8 m s?1. The turbine was operated with fixed rotational speed. The energy at the blade is concentrated in spectral bands centred at multiples of the rotational frequency up to three times the rotational frequency. The highest fatigue load reduction was achieved when the inflow sensor was placed at the outer parts of the blade. In the best case, the reduction of the local fatigue loads induced by the blade sectional normal force was 60%. The control method gave the highest fatigue load reductions in conditions with strong wind shear. The demands for the flap actuator in terms of deflection angles was ±10°. The requirements in terms of the flap deflection velocity depend mainly on the inflow turbulence intensity. The maximum value was ±40°s?1 for 20% inflow turbulence intensity. Unsteady aerodynamic effects seem to be negligible. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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The paper proposes a smart rotor configuration where adaptive trailing edge flaps (ATEFs) are employed for active alleviation of the aerodynamic loads on the blades of the NREL 5 MW reference turbine. The flaps extend for 20% of the blade length and are controlled by a linear quadratic (LQ) algorithm based on measurements of the blade root flapwise bending moment. The control algorithm includes frequency weighting to discourage flap activity at frequencies higher than 0.5 Hz. The linear model required by the LQ algorithm is obtained from subspace system identification; periodic disturbance signals described by simple functions of the blade azimuthal position are included in the identification to avoid biases from the periodic load variations observed on a rotating blade. The LQ controller uses the same periodic disturbance signals to handle anticipation of the loads periodic component. The effects of active flap control are assessed with aeroelastic simulations of the turbine in normal operation conditions, as prescribed by the International Electrotechnical Commission standard. The turbine lifetime fatigue damage equivalent loads provide a convenient summary of the results achieved with ATEF control: 10% reduction of the blade root flapwise bending moment is reported in the simplest control configuration, whereas reductions of approximately 14% are achieved by including periodic loads anticipation. The simulations also highlight impacts on the fatigue damage loads in other parts of the structure, in particular, an increase of the blade torsion moment and a reduction of the tower fore‐aft loads. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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In this work, a 2D aero‐servo‐elastic model of an airfoil section with 3 degrees of freedom (DOF) based on the 2D CFD solver EllipSys2D to calculate the aerodynamic forces is utilized to calculate the load reduction potential of an airfoil equipped with an adaptive trailing edge flap (ATEF) and subjected to a turbulent inflow signal. The employed airfoil model corresponds to a successfully tested prototype airfoil where piezoelectric actuators were used for the flapping. In the present investigation two possible control methods for the flap are compared in their ability to reduce the fluctuating normal forces on the airfoil due to a 4 s turbulent inflow signal and the best location of the measurement point for the respective control input is determined. While Control 1 uses the measurements of a Pitot tube mounted in front of the leading edge (LE) as input, Control 2 uses the pressure difference between the pressure and suction side of the airfoil measured at a certain chord position. Control 1 achieves its maximum load reduction of RStd(Fy) = 76.7% for the shortest Pitot tube of the test, i.e. a Pitot tube with a length of 0.05% of the chord length. Control 2 shows the highest load reduction of RStd(Fy) = 77.7% when the pressure difference is measured at a chord position of approximately 15%. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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J. W. van Wingerden A. W. Hulskamp T. Barlas B. Marrant G. A. M. van Kuik D.‐P. Molenaar M. Verhaegen 《风能》2008,11(3):265-280
The trend with offshore wind turbines is to increase the rotor diameter as much as possible to decrease the costs per kilowatt‐hour. The increasing dimensions have led to the relative increase of the loads on the wind turbine structure. Because of the increasing rotor size and the spatial load variations along the blade, it is necessary to react to turbulence in a more detailed way; each blade separately and at several separate radial distances. In this paper, a proof of concept study is performed to show the feasibility of the load alleviation abilities of a ‘Smart’ blade, i.e. a blade equipped with a number of control devices that locally change the lift profile on the blade, combined with appropriate sensors and feedback controllers. Theoretical and experimental models are developed of a scaled non‐rotating rotor blade which is equipped with two trailing edge flaps and strain sensors to facilitate feedback control. A pitch actuator is used to induce disturbances with a similar character as a gust or turbulence. A feedback controller based on classical loop shaping is designed that minimizes the root bending moment in the flapping direction. We show that with appropriate control techniques, the loads for periodic disturbances and for turbulence generated disturbances can be reduced up to 90 and 55%, respectively. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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为研究尾缘襟翼在风力机主动降载和功率控制方面的效果,以NREL 5 MW参考风力机为研究对象,在改进FAST的带有尾缘襟翼的气弹仿真平台基础上,使用改进动态矩阵控制(DMC)方法,将独立襟翼控制器与集成襟翼控制器结合,提出DMC多目标襟翼控制策略。仿真结果表明,稳定风况及湍流风况下,独立襟翼控制器均能很好地降低叶根疲劳载荷;阶跃风况下与传统DMC控制器相比,使用改进DMC的集成襟翼控制器对叶轮功率的控制效果更好;湍流风况下与PID襟翼控制策略相比,DMC多目标襟翼控制策略有更好的控制效果,能使叶根弯矩标准差降低52.64%,叶轮功率标准差降低74.62%。 相似文献
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Anargyros A. Karakalas Dimitris I. Manolas Theodoros T. Machairas Vasilis A. Riziotis Dimitris A. Saravanos 《风能》2019,22(5):620-637
Upscaling of wind turbine blades calls for implementation of innovative active load control concepts that will facilitate the flawless operation of the machine and reduce the fatigue and ultimate loads that hinder its service life. Based on aeroelastic simulations that prove the enhanced capabilities of combined individual pitch and individual flap control at global wind turbine scale level, a shape adaptive concept that encompasses an articulated mechanism consisting of two subparts is presented. Shape memory alloy (SMA) actuators are investigated and assessed as means to control the shape adaptive mechanism at airfoil section level in order to alleviate the developed structural loads. The concept is embedded in the trailing edge region of the blade of a 10‐MW horizontal axis wind turbine and acts as a flap mechanism. Numerical simulations are performed considering various wind velocities and morphing target shapes and trajectories for both normal and extreme turbulence conditions. The results prove the potential of the concept, since the SMA controlled actuators can accurately follow the target trajectories. Power requirements are estimated at 0.22% of the AEP of the machine, while fatigue and ultimate load reduction of the flap‐wise bending moment at the blade root is 27.6% and 7.4%, respectively. 相似文献
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The effects of modifying the inboard portion of the experimental NREL Phase VI rotor using a thickened, blunt trailing‐edge (or flatback) version of the S809 design airfoil are studied using a compressible, three‐dimensional, Reynolds‐averaged Navier–Stokes method. A motivation for using such a thicker airfoil design coupled with a blunt trailing edge is to alleviate structural constraints while reducing blade weight and maintaining the power performance of the rotor. The numerical results for the baseline Phase VI rotor are benchmarked against wind tunnel measurements obtained at freestream velocities of 5, 7 and 10ms?1. The calculated results for the modified rotor are compared against those of the baseline rotor. The results of this study demonstrate that a thick, blunt trailing‐edge blade profile is viable as a bridge to connect structural requirements with aerodynamic performance in designing future wind turbine rotors. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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分布式风-光互补能源利用系统 总被引：2，自引：0，他引：2
提出充分利用风能和太阳能的互补性,设计了风能和太阳能联合供能系统在运行中能量产生、储备、利用等各个环节的工作方式,实现可靠、高效地运行,为用户提供了生活用电与供热。该系统很好地利用了风-光可再生资源在季节、天气、地域上的互补性,可拓展风能和太阳能经济利用的范围。该系统在风-光丰富的广大农村地区具有很好的应用和发展前景。 相似文献
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根据相关机构的统计数据,对2008年全球及国内风电发展的基本情况进行了分析.全球的风电继续保持快速发展的势头,2008年美国与中国是全球新增风电装机容量最多的2个国家,风电总装机容量分列全球第l和第4;风电装机进一步呈向风能资源丰富的地区集中的发展趋势,并且风电机组的单机容量继续增大,建议应对风电输送与消纳问题进行定量化的研究与分析. 相似文献
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Paul Gipe 《Renewable Energy》1998,15(1-4)
An summary of the growth in wind energy generation worldwide. 相似文献
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近年来,清洁能源得到广泛应用与发展,大力发展开发清洁能源,可以优化能源配置结构,保护自然环境。结合三明地区能源开发实际情况,系统分析发展清洁能源如何加快三明电网发展,并具体阐述了光伏发电技术、风力发电技术、小水电技术和余热发电技术等。 相似文献
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为提高垂直轴风力机（vertical axis wind turbine, VAWT）的气动效率,受圆柱后分流板可减少升阻力系数波动的启发,本文提出尾缘后分流板的新型流动控制方式,以NACA0015翼型为对象,研究分流板长度以及其与翼型的间隙对翼型气动性能的影响;同时探究分流板在不同叶尖速比工况下对VAWT气动效率的影响。结果表明：尾缘后分流板对翼型可起到增升减阻的效果,带尾缘后分流板的VAWT可有效提高其风能利用率,在低尖速比工况下,风能利用率均高于原始风力机,在高尖速比工况下,风能利用率最大提高约25.78%。同时发现,尾缘后分流板的存在有利于VAWT的尾流恢复,在相同尖速比工况下,带有尾缘后分流板的VAWT的尾迹长度短于原始风力机。 相似文献
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阐述风能和太阳能是丰富清洁的可再生能源,风力发电和太阳能光伏发电是重要的后续能源,将为能源结构调整和环境保护做出巨大贡献。介绍国内外风能与太阳能资源,分析国内外风力及太阳能光伏发电现状,论述其发展趋势及需要解决的问题。针对风能与太阳能的特点,指出风力与太阳能互补发电比单一发电方式更优越,并介绍风力与太阳能光伏互补发电的研究现状及进一步发展所要做的努力。 相似文献
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可再生能源系统的能源储存 总被引：3，自引：0，他引：3
介绍了电能储存在三种商业模式和各种储能技术包括水力蓄能，压缩空气蓄能，超导磁力储能，流体电池组，蓄电池，飞轮蓄能，储热，在此基础上，对非电网可再生能源储能系统特别是风力发电和储能方案进行了详细的分析，认为这是非常适合偏远地区的新技术。 相似文献
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This paper presents a comparative study between the so‐called BPM and TNO models for the prediction of aerofoil trailing‐edge noise with particular emphasis on wind‐turbine applications (the BPM model is named after Brooks, Pope and Marcolini who first proposed the model, and the TNO model is named after the TNO institute of Applied Physics where it was first proposed). In this work, two enhanced versions of the BPM model are proposed, and their performances are compared against two recent anisotropic TNO models that require more detailed boundary‐layer information than the BPM‐based models. The two current enhanced models are denoted as BPMM‐PVII and BPMM‐BLkω, where the former uses a panel method with viscous‐inviscid interaction implemented (PVII) for boundary‐layer calculations, the latter estimates the boundary‐layer (BL) properties using a two‐dimensional k‐ω turbulence model (kω), and BPMM stands for BPM‐Modified. By comparing the predicted sound spectra with existing measurement data for seven different aerofoils tested in the current study, it is shown that the BPMM‐PVII model exhibits superior results to those by the other models for most cases despite the simplicity without considering anisotropy. The BPMM‐PVII model is then combined with Prandtl's nonlinear lifting‐line theory to calculate and investigate three‐dimensional rotor noise characteristics of an NREL UAE Phase‐VI wind turbine (NREL UAE stand for the National Renewable Energy Laboratory Unsteady Aerodynamic Experiment). It is demonstrated that the current approach may provide an efficient solution for the prediction of rotor aerodynamics and noise facilitating industrial design and development for low‐noise wind turbines. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
20.
尾缘襟翼对风力机翼型气动特性影响研究 总被引：1，自引：0，他引：1
尾缘襟翼(TEF)因其对翼型气动特性的调控能力,被认为是降低叶片疲劳和局部载荷最具可行性的气动控制部件。对TEF进行建模,采用Xfoil和CFD软件分析了TEF对翼型气动特性的影响及其机理,并从叶素理论角度对变化来流下TEF的减载效果进行了验证,结果表明:TEF位于不同摆角时翼型升阻力系数均有不同程度的变化,TEF可有效实现对翼型气动特性的主动控制;TEF摆动改变了翼型表面的静压分布和流动状态,进而对翼型升阻力和失速攻角产生影响;TEF可快速有效降低风速突然增加后的叶素受力,进而控制并减小叶片载荷。 相似文献