75kW风力发电机组的研制

详细介绍了７５ｋＷ风力发电机组的基本性能、机械结构设计和特点、电控系统的软硬件设计和特点、安全保护措施。     

基于状态码的风力发电机组可利用率计算

风力发电机组的可利用率是衡量风力发电机组可靠性的一个重要指标。目前国内使用可利用率计算方法各式各样,至今没有统一的标准。提出了一种基于风机现地控制系统状态码处理的可利用率计算方法,通过对状态码可利用属性的细化,实现了机组可利用率的精确计算。     

大型风力发电机组柔体叶轮动力学分析

选取叶轮系统为研究对象,通过ANSYS分析获得关键部件的模态中性文件(MNF);在ADAMS中建立叶轮多柔体分析模型,经过对叶轮模型风载荷的分析、简化、加载、动力学仿真分析等,获得各种更真实、更准确的柔体叶轮的动力学参数,为后续大型风力发电机组关键部件的设计、分析、优化提供可靠的载荷依据,从而探索了一种对大型风力发电机组进行多柔体动力学分析研究的新思路,进而设计出高性能的大型风力发电机组。     

大型并网风力发电机组国产化探讨──FD24—200kW风力发电机组研制总结

总结了ＦＤ２４一２００ｋＷ风力发电机组研制、调试工作的经验,讨论了国产化风机及其运行管理的可行性,并提出一种国产化最佳模式的设想。     

基于多时间尺度的并网型风力发电机组模型

对采用异步发电机与电网直接相连的风力发电机组进行了建模,并利用多时间尺度系统理论对模型进行了简化,采用仿真方法验证了简化后的模型的有效性。此外,还对整个风力发电系统的运行方式,补偿电容的动态作用进行了详细的分析,说明了此种风电机组的优缺点。     

大型风力发电机组控制器应对电网故障的措施

介绍了在600kW风力发电机组控制器关键技术的产业化项目中，控制器对各类电网故障采取的检测与安全保护措施。重点介绍了对电网停电这一特殊故障，控制系统所果取的电网停电检测、不间断电源供电、控制器保护以及数据记录等技术，并在实践中得到了验证。     

超大功率风力发电机组塔筒屈曲分析

以某型8 MW风力发电机组塔筒为对象,采用有限元方法开展超大功率风力发电机组塔筒屈曲特性分析.建立塔筒门洞段有限元模型,研究门框对塔筒屈曲稳定性的影响,结果表明:门洞加框能提高塔筒屈曲稳定性.为进一步提高塔筒屈曲稳定性,提出塔筒内壁设置加强筋的强化设计方法,研究加筋数目、加筋尺寸与塔筒屈曲稳定性的作用规律,结果表明:环...     

大型风力发电机组塔架优化设计

鉴于塔架对风力发电机组的承载能力、使用寿命与安全的影响,因此对塔架进行科学、合理的设计尤为重要。提出了风力发电机组塔架的设计思路,总结了静强度、屈曲稳定及模态分析等理论基础的特点,通过整合这些理论基础给出了优化设计步骤,并以湘潭电机股份有限公司某大型风机为例,采用Matlab对塔架进行了优化设计。结果表明,采用基础理论对塔架进行优化设计是简单有效的方法之一,且在满足各项安全指标的前提下,有效地控制了塔架重量,适合推广应用。     

Reliability analysis for wind turbines

Modern wind turbines are complex aerodynamic, mechanical and electrical machines incorporating sophisticated control systems. Wind turbines have been erected in increasing numbers in Europe, the USA and elsewhere. In Europe, Germany and Denmark have played a particularly prominent part in developing the technology, and both countries have installed large numbers of turbines. This article is concerned with understanding the historic reliability of modern wind turbines. The prime objective of the work is to extract information from existing data so that the reliability of large wind turbines can be predicted, particularly when installed offshore in the future. The article uses data collected from the Windstats survey to analyse the reliability of wind turbine components from historic German and Danish data. Windstats data have characteristics common to practical reliability surveys; for example, the number of failures is collected for each interval but the number of turbines varies in each interval. In this article, the authors use reliability analysis methods which are not only applicable to wind turbines but relate to any repairable system. Particular care is taken to compare results from the two populations to consider the validity of the data. The main purpose of the article is to discuss the practical methods of predicting large‐wind‐turbine reliability using grouped survey data from Windstats and to show how turbine design, turbine configuration, time, weather and possibly maintenance can affect the extracted results. Copyright © 2006 John Wiley &Sons, Ltd.     

Computational analysis of diffuser-augmented wind turbines

Diffuser-augmented wind turbines are suitable candiates for the generation of electricity from jet-stream winds. A blade element, computational analysis is developed that includes wake rotation effects and blade Reynolds number effects. The influence of the diffuser is allowed for by introducing empirical values for the diffuser efficiency and exit-plane pressure coefficient. Good agreement is obtained for power coefficient and turbine axial velocity with experimental results. The use of screens to simulate the turbine is found to overestimate the turbine output by neglecting blade profile drag but to underestimate turbine output by neglecting favourable rotational influences on diffuser efficiency. Maximum power is delivered with a solidity ratio of 0.10 to 0.15 depending on the aerofoil section used.     

Synchronous mode operation of DFIG based wind turbines for improvement of power system inertia

Inertia emulation methods exist to compensate for the reduced inertial support provided by doubly fed induction generator (DFIG) based wind turbines. Instead of emulating inertia, this paper proposes to temporarily convert DFIGs to synchronous generators, enabling supply of real inertia to the system. In order to achieve this, the voltage supplied to the DFIG rotor needs to be made independent of the grid frequency. Feeding the rotor with a fixed dc voltage while it is rotating at synchronous speed enables the DFIG to operate in synchronism with the grid and couple the inertia of its rotating mass to the power system. The rotor side converter of a DFIG can be controlled to function as the dc voltage source, allowing convenient switching between the two operation modes according to system requirements.     

Failure rate,repair time and unscheduled O&M cost analysis of offshore wind turbines

Determining and understanding offshore wind turbine failure rates and resource requirement for repair are vital for modelling and reducing O&M costs and in turn reducing the cost of energy. While few offshore failure rates have been published in the past even less details on resource requirement for repair exist in the public domain. Based on ~350 offshore wind turbines throughout Europe this paper provides failure rates for the overall wind turbine and its sub‐assemblies. It also provides failure rates by year of operation, cost category and failure modes for the components/sub‐assemblies that are the highest contributor to the overall failure rate. Repair times, average repair costs and average number of technicians required for repair are also detailed in this paper. An onshore to offshore failure rate comparison is carried out for generators and converters based on this analysis and an analysis carried out in a past publication. The results of this paper will contribute to offshore wind O&M cost and resource modelling and aid in better decision making for O&M planners and managers. Copyright © 2015 John Wiley & Sons, Ltd.     

Dynamic wind estimation based control for small wind turbines

We introduce a novel scheme for small wind turbines that gives dynamic estimation of wind speed from rotor angular velocity measurements. The estimation proceeds in two different dynamic observers, one giving a valid estimate for higher Tip Speed Ratios (TSRs) and which we call the Upper Wind Estimator (UWE) and the other called the Lower Wind Estimator (LWE) valid for lower TSRs. The meaning of “higher” and “lower”, and the precise regions of validity, are quantified. We further propose a coordinated control scheme using the UWE. Simulations are presented showing closed-loop performance of the turbine and the estimators both in the optimal TSR regulation condition, and the dynamic power-shedding condition caused by a wind gust. An analytic analysis of closed-loop stability and of the convergence and bias properties of the estimator is provided. Empirical data showing performance on a real turbine is also presented.     

风电机组高电压穿越技术研究

随着风电入网比例的增大,风电入网导则也逐步发展建立,入网导则的主要目的是确保风电场的入网运行不影响整个电力系统的稳定。风电场低电压穿越(LVRT)已作为热点技术被广泛关注,但风电机组风电场高电压穿越没有得到相应的重视。文章基于常见机组类型,首先介绍了风电机高电压穿越(HVRT)方面现有电网要求,给出了现有风电场高电压穿越能力要求曲线,对风电机组高电压穿越软硬件的技术方案。最后仿真证明了所提技术方案的正确性,分析了该技术方案对风机运行成本方面的可行性。     

Digital tuft analysis of stall on operational wind turbines

Operational wind turbines are exposed to dynamic inflow conditions because of, for instance, atmospheric turbulence and wind shear. In order to understand the resulting three‐dimensional and transient aerodynamics effects at a site, a 10m stall‐regulated upwind two‐bladed wind turbine was instrumented for a novel digital tuft flow visualization study. High definition video of a tufted blade was acquired during wind turbine operation in the field, and a novel digital image processing algorithm calculated the blade stall directly from the video. After processing O(10⁵) sequential images, the algorithm achieved a ?5% bias error compared with previous manual analysis methods. With increasing wind speed (5m/s to 20m/s) the fraction of tufts exhibiting stalled flow increased from 5% to 40% on the outboard 40% of the blade. The independently measured instantaneous turbine power production correlates highly with the stall fraction. Some azimuthal variation in the stall fraction associated with dynamic stall induced by vertical wind shear was seen with a maximum in the 45–90° azimuthal location. The high detail, quantitative image processing method demonstrated good agreement with the expected behaviour for a stall‐regulated wind turbine and revealed azimuthal variation because of shear‐induced dynamic stall. The amount of reliable blade stall data to be obtained from digital tuft visualization has hereby been vastly increased. Copyright © 2015 John Wiley & Sons, Ltd.     

一种基于模型修正的海上风电桩基弱化识别方法

海上风电桩基弱化对风机整体结构动力特性影响较大,严重时会造成风机停机,甚至结构失效。文章对海上风电支撑结构的桩基弱化识别方法进行了研究。首先,基于等效固定桩模型,构建了桩基边界单元刚度矩阵,提出了一种基于有限元模型修正的桩基弱化识别方法;其次,推荐了一种迭代修正过程,用于处理实测模态空间不完备问题;最后,以某个3.0 MW的Tripod海上风电支撑结构为算例,对该方法的有效性进行了数值验证。结果表明,在桩侧无任何测点的情况下,该方法可准确地识别桩基的侧向刚度弱化,且具有较强的噪声鲁棒性;另外,结合一定的损伤定位技术,该方法可对上部结构的损伤和桩基的弱化进行同时识别。     

基于应变模态的风机叶片损伤诊断研究

针对多种受损工况下的风机叶片损伤诊断问题,文章基于模态理论对受损前和受损后的风机叶片进行位移和应变模态分析.首先建立风机叶片的三维模型并对其进行有限元分析;然后模拟叶片两位置不同的损伤状况,比较各工况下位移模态曲线、应变模态曲线和应变模态差分曲线在受损前后的变化规律,进而对叶片进行损伤辨识;最后选取应变模态变化率和由差...     

A torque matched aerodynamic performance analysis method for the horizontal axis wind turbines

An analysis method is developed to test the operational performance of a horizontal axis wind turbines. The rotor is constrained to the torque–speed characteristic of the coupled generator. Therefore, the operational conditions are realized by matching the torque generated by the turbine over a selected range of incoming wind velocity to that needed to rotate the generator. The backbone of the analysis method is a combination of Schmitz' and blade element momentum (BEM) theories. The torque matching is achieved by gradient‐based optimization method, which finds correct wind speed at a given rotational speed of the rotor. The combination of Schmitz and BEM serves to exclude the BEM iterations for the calculation of interference factors. Instead, the relative angle is found iteratively along the span. The profile and tip losses, which are empirical, are included in the analysis. Hence, the torque at a given wind speed and rotational speed can be calculated by integrating semi‐analytical equations along the blade span. The torque calculation method is computationally cheap and therefore allows many iterations needed during torque matching. The developed analysis method is verified experimentally by testing the output power and rotational speed of an existing wind turbine model in the wind tunnel. The generator's torque rotational speed characteristic is found by a separate experimental set‐up. Comparison of experiments with the results of the analysis method shows a good agreement. Copyright © 2013 John Wiley & Sons, Ltd.