地震对风力发电机组塔架设计的影响

以国内典型的82m风轮直径、70m轮毂高度的1.5MW风力发电机组为例,介绍了Ⅷ级烈度地震载荷的计算方法,通过有限元法(FEA)建模计算了风力发电机组塔架的自然模态位移和地震载荷,并利用得出的计算结果确定地震对塔架设计的影响。实例应用结果表明,Ⅷ级烈度地震引起的载荷叠加值小于塔架的设计极限载荷,塔架设计能满足安装在烈度Ⅰ～Ⅷ地震地区的安全要求。     

大型风力发电机组变桨距系统结构可靠性设计研究

随着风力发电技术的不断发展,大功率、长叶片已逐渐成为大型风力发电机组的主要特征和发展方向,以持续提升风能利用的经济性。风力发电机组大型化带来叶片长度和重量的显著增加,风轮每旋转一周,在低速轴上的受力和作用在叶片上的重力均会出现周期性变化,同时,在风轮旋转平面上,因风切变、塔影效应和湍流的作用而产生循环变化的载荷。风力发电机组大型化必然带来机组疲劳载荷的增加,疲劳载荷是风力发电机组在全风速范围内运行所产生的典型载荷循环,循环的数量正比于各种风速下机组发电运行的时间,决定着部件的设计使用寿命。为进一步研究风切变、塔影效应、叶片重力、叶片推力载荷对大风轮直径机组叶根疲劳载荷所产生的影响,文章通过对风轮运行载荷分析和系统仿真,对变桨传动系统结构有限元计算和分析,研讨影响变桨传动系统可靠运行的主要因素,为大型风力发电机组变桨传动系统可靠性设计提供参考。     

风电机组塔架极限风载荷计算及对比研究

以某2 MW水平轴风力发电机组为计算模型,分别采用GH Bladed软件和日本《风力发电设备塔架结构设计指南及解说》对该风电机组塔架的极限风载荷进行计算,并研究在正常发电工况和暴风工况下2种计算方法的差异。结果表明,由2种计算方法得到的正常发电工况下的极限风载荷均大于暴风工况,由GH Bladed软件得到的极限风载荷计算结果偏大。造成极限风载荷差异的主要原因是2种计算方法的风况条件、工况种类及理论基础不同造成的。对于风力发电机塔架这种典型的"高鸡腿哑铃式"高耸结构因其塔顶部位受风轮、机舱的影响较大,采用GH Bladed软件计算结果更精确。     

大型风力发电机组塔架联接螺栓最大工作载荷的计算

通过风力发电机组塔架联接螺栓所受的载荷种类、特点,对塔架联接螺栓受力状态进行分析,并根据螺栓的分布规律推导出联接螺栓最大工作载荷的精确、简便的计算公式,可供相关设计人员参考.     

基于激光测风雷达的风速前馈控制算法设计

文章提出了基于激光测风雷达的风速前馈控制算法设计,其特点是通过激光雷达准确有效地测得风力发电机组前方一定距离的风速、风向信号,并把所测信号引入到原有变桨控制算法中,设计了风速前馈控制器,实现变桨速率前馈补偿.以国产某1.5 MW风力发电机组设计为例,基于Bladed软件平台对所采用的算法进行仿真验证.结果表明,在来流作用于风轮之前,控制器就已经接收到超前信号,提前准备变桨动作,避免或大大减少风力发电机组的超速故障,降低了机组载荷,提高了风力发电机组在极端风况下的安全性,进而有助于提高发电量,改善风力发电机组的运行效率.     

兆瓦级风力发电机组的稳定性分析

建立了风轮转子/塔架系统的运动方程,并通过对该方程进行解耦分析得到了机组的振动模态.在对兆瓦级风力发电机组的振动模态计算、分析的基础上,给出了系统固有频率的最低点;系统工作转速与系统固有频率的交汇点;塔架的半径、壁厚与系统固有频率的关系.以上研究对我国自主设计兆瓦级风力发电机组提供了一定的理论依据.     

风力发电机组风轮的主要设计参数探讨

风轮是风力发电机组的关键部套,其特性对于机组性能和成本具有重要的意义.本文通过分析风力发电机组风轮的主要设计参数的选定次序、对性能的影响以及各参数间相互制约的关系,提出确定概念设计中风轮主要设计参数的选定次序、计算及优化方法,对风力发电机组的概念设计有一定的参考意义.     

基于混合灵敏度H_∞的海上风力发电机组变桨控制及振动抑制

针对海上风力发电机组输出功率波动大和塔架振动明显的问题,设计了混合灵敏度H∞变桨控制器,并引入塔架前后加速度反馈控制,基于SUT-3000双馈风力发电机组模型,利用GH_Bladed软件进行仿真验证。仿真结果表明,在该控制策略作用下,海上风力发电机组输出功率比传统PI控制方法波动更小,保证了海上风力发电机组在高风速运行时输出功率的稳定性,同时降低了塔架前后振动响应。     

水平轴风力机锥形塔筒的静动态特性研究

根据叶素动量理论,考虑三维紊流风场、Beddoes-Leishman动态失速模型、惯性载荷及重力载荷计算了风力机的整机载荷,进而得到塔架动态载荷的极限工况,针对塔架的结构特点,再应用有限元理论,对水平轴风力发电机组塔架的静态(强度)、动态(屈曲、模态)特性进行了研究。以一台1.5MW水平轴风力发电机组为例,计算了塔架在不同极限工况下的载荷,并对塔筒进行了强度、屈曲和模态分析,得到了具有较大工程实用价值的塔筒静动态分析方法。     

基于风力发电机组载荷测试的设计载荷验证

根据风力发电机组型式认证及试验相关要求,介绍了一种应用风力发电机组载荷测试方法对仿真设计进行验证的实例。结合实际测试的外部条件,如风速、风向、温度、气压等以及风力发电机组本身的电气模型,运用BLADED软件进行计算与仿真,得到启机、正常停机、脱网、超速等不同工况下的载荷仿真结果。通过仿真结果与测试结果的对比,验证风力发电机组的设计载荷。同时,通过比较20年疲劳载荷谱,可以对风力发电机组的使用寿命与安全性进行确认,该研究对于优化风力发电机组的载荷设计具有重要意义。     

角度风对转角塔水平荷载的影响

分析了转角杆塔设计时的荷载取值,将杆塔水平荷载分为水平风压荷载和水平张力荷载2种,考虑风对转角塔2侧电线的作用及对电线张力的影响,得出角度风作用下转角杆塔的综合水平荷载公式,并根据实际算例,探讨了杆塔最大水平荷载与大风角度的关系。结果表明,对于转角度数较大的转角杆塔,有必要根据实际情况计算角度风对水平荷载的影响。     

Modeling,control, and simulation of dual rotor wind turbine generator system

A new wind turbine generator system (WTGS) is introduced, and its mathematical model, blade pitch control scheme, and nonlinear simulation software for the performance prediction are presented. The notable feature of WTGS is that it consists of two rotor systems positioned horizontally at upwind and downwind locations, and a generator installed vertically inside the tower. In this paper, this new WTGS is treated as a constrained multi-body system, and the equations of motion are obtained by using the multi-body dynamics approach. Aerodynamic forces and torques generated from each of rotor blades are calculated using the blade element theory. Various pitch control schemes depending on the wind speed and the main rotor's rotational speed are implemented. A relatively simple model for the load torque is obtained by using the test data of the doubly fed induction generator adopted in the new WTGS. Finally, FORTRAN and Matlab/Simulink-based hybrid simulation software is developed and used to predict and analyze the performance of the WTGS.     

考虑时变气动阻尼的风电机组塔筒地震响应分析

为了分析时变气动阻尼对风电机组塔筒地震响应的影响,首先分析了塔筒所承受的地震载荷和气动载荷,然后基于气动载荷和相对风速之间的导数关系推导了塔筒前后和左右方向上的时变气动阻尼计算方法,将地震加速度和时变气动阻尼引入到塔筒动力学运动方程中并进行时域求解,以某2.0MW风电机组塔筒为例进行地震响应计算,分析了影响气动阻尼大小的翼型气动特性,并着重研究了地震作用下时变气动阻尼对塔顶振动位移的影响程度,为风电机组塔筒抗震设计提供一定参考。     

Wind gust detection and load mitigation using artificial neural networks assisted control

The design of a wind turbine implies the simulation of definite conditions as specified in the standards. Among those operational conditions, rare events such as extreme gusts or external faults are included, which may cause high structural loads. Such extreme design load cases usually drive the design of some of the main components of the wind turbine: tower, blades and mainframe. Two different strategies are hence presented to mitigate the loads, deriving from extreme load cases, on the basis of the detection of wind gusts by means of ad hoc synthesized artificial neural networks. This tool is embedded into the main control algorithm and allows it to detect the gust in advance, to anticipate the control reaction, and by doing so reducing extreme loads. One of the strategies performs a controlled stop when wind gust is detected. The other rides through wind gusts without stopping, i.e., without affecting the wind turbine normal operation. Aeroelastic simulations of the Alstom Wind's wind turbines using these techniques have shown significant reductions in the extreme loads for all standard IEC 61400‐1, edition 2 DLC 1.6 cases. In particular, the overall ultimate loads are largely reduced for blade root and tower base bending moments, with a direct impact on the structural design of those components. Copyright © 2013 John Wiley & Sons, Ltd.     

并网风电机组输出电能闪变和谐波指标的比较与分析

对根据IEC 61400-21标准进行测试的四款风电机组,即750 kW定桨失速型机组、2 MW变速恒频全馈机组、2.5 MW变速恒频双馈机组和运达（WD77-1500 A/1500 kW）变速恒频双馈机组的电能质量测试和评估报告进行了分析,通过比较风电机组闪变的测量值、谐波电流值,可对各种风电机组在不同方面的性能有一定的了解。     

Effect of rotor–tower interaction,tilt angle,and yaw misalignment on the aeroelasticity of a large horizontal axis wind turbine with composite blades

This paper presents a detailed analysis of the rotor–tower interaction and the effects of the rotor's tilt angle and yaw misalignment on a large horizontal axis wind turbine. A high‐fidelity aeroelastic model is employed, coupling computational fluid dynamics (CFD) and structural mechanics (CSM). The wind velocity stratification induced by the atmospheric boundary layer (ABL) is modeled. On the CSM side, the complex composite structure of each blade is accurately modeled using shell elements. The rotor–tower interaction is analyzed by comparing results of a rotor‐only simulation and a full‐machine simulation, observing a sudden drop in loads, deformations, and power production of each blade, when passing in front of the tower. Subsequently, a tilt angle is introduced on the rotor, and its effect on blade displacements, loads, and performance is studied, representing a novelty with respect to the available literature. The tilt angle leads to a different contribution of gravity to the blade deformations, sensibly affecting the stresses in the composite material. Lastly, a yaw misalignment is introduced with respect to the incoming wind, and the resulting changes in the blade solicitations are analyzed. In particular, a reduction of the blade axial displacement amplitude during each revolution is observed.     

A design strategy for the improvement of an existing 300KW WTGS rotor blade

This paper presents our design concept of a new rotor blade for an existing 300 kW WTGS with a horizontal axis rotor. This two-bladed WTGS is evaluated to have rather poor performance in terms of annual output due to the deficiencies in aerodynamic design of blade and its high noise emission level which restricts the time range of operation. The new blade must be adaptive to the existing hardware, e.g. the flange for installation and the hub and tower to assure a clearance in case of blade feathering. In order to reduce noise, and at same time, achieve high performance at the given tip speed ratio, a narrow design path was found which gives compromise among the conflicting requirements. This paper presents the outcome of this design with the airfoil, plan form and twist distribution which can attain the Betz limit on the blade from 30% to 95% radial position at the design tip speed ratio of 7.0.     

Evaluation of pressure coefficients and estimation of air flow rates in buildings employing wind towers

Wind pressure coefficients at various openings of a wind tower were determined by testing a scale model of the building in a boundary layer wind tunnel. Wind towers (or Baud-Geers) are structures which have been employed in Iran and neighbouring countries for natural ventilation and passive cooling. Tests were conducted on an isolated tower, the tower and adjoining house, and the tower and house surrounded by a courtyard. The wind pressure coefficients at the tower and house openings were determined at various wind angles for two types of terrain: suburban and open country. The air flow rates were then estimated from a knowledge of the wind pressure coefficients at the building apertures. It was concluded that the presence of a courtyard around the structure and the angle of incidence of the wind influence the rate and the direction of air flowing from the tower to the house. If leeward openings of the tower can be closed (for example, by automatic dampers) restricting the air leaving these apertures, the air flow rate from the tower to the house can be greatly increased. The results of this investigation are believed to provide assistance to architects and engineers in the design of wind towers for desired ventilation rates in buildings.     

Wind turbine generator systems. The supply chain in China: Status and problems

Wind turbine generator systems (WTGS) manufacture is booming in China. The key to success of the wind turbine generator industry is to construct the supply chain. However few papers focus on the supply chain. In China, many enterprises have started to manufacture the wind turbine generator system and the components. The supply chain of the wind turbine generator system is not well established in China. Many key components of WTGS still need to be imported, such as the principal axis bearing and electrical control systems. We review the status of wind turbine generator system manufacturing and analyze the problems of the supply chain in China. We analyze the problems about the supply chain from a macroscopic view. The aims of this paper are to let more scholars and experts know the status of the WTGS supply chain and to do something for building a successful industry in China.     

极限环境载荷诱导风力机结构振动影响分析

风力机桩基、塔架及连接部件构成的支撑结构属顶部承担较大质量的力学结构,地震对其造成的影响远大于常规建筑.针对上述问题,基于NREL开发计算平台,联合TurbSim、AeroDyn、FAST及Seismic,对变风载荷、变地震载荷(波形、强度)下的风力机动力学响应进行研究.发现:地震横波对风力机结构响应造成剧烈影响,纵波...