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为解决海上风电基础结构存在的材料强度利用率低、应力集中等问题,提出一种新型桁架式海上风电支撑结构.建立设计水深为10m的三维有限元模型,利用ANSYS有限元分析软件首先进行结构模态分析,得出固有频率值,以确定结构不会与风机的工作频率耦合发生共振.对包括风机运转载荷在内的6种不同工况进行静力和动力分析,得到静力分析结果和单元的时程曲线,与传统的单柱式进行比较,结果表明:新型海上风电支撑结构动力分析结果与静力相比,顶部最大位移增大0.002m,最大yon Mises应力增大2.3MPa,低于相同刚度单柱式结构的0.026m、25.7MPa,具有良好的动力性能. 相似文献
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大容量海上风电机组的接入改变了传统电力系统结构,给电网带来了谐波等问题,影响了电能质量。为抑制海上风电机组产生的低次谐波,文章首先建立了海上风电机组并网电流的低次谐波理论模型;然后,在仿真软件ETAP上搭建海上风电机组仿真模型,验证不同出力情况下风电场的输出谐波特性;最后,基于风电场输出谐波特性,提出变异系数(Variation Coefficient,VC)综合赋权法对风电场有源滤波器(APF)进行优化配置,提升了风电场谐波的治理效果。基于实际算例验证了所提方法的有效性。 相似文献
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5 MW双馈风电机组低电压穿越的仿真分析 总被引:2,自引:0,他引:2
针对海上风力发电机组安全可靠运行要求的发展趋势,本文在阐述双馈风电机组控制原理的基础上,建立了双馈发电机及其变流器的控制模型。其次,在分析电力系统对并网风电机组低电压穿越原理基础上,比较分析了双馈风电机组低电压穿越的各种控制技术方案。最后,结合海上用5.0 MW双馈风力发电机组电气参数,对2种典型低电压穿越的转子电路保护措施进行了仿真比较。分析结果表明,采用二极管整流桥加IGBT和保护电阻构成斩波器的措施具有较好的暂态控制效果。 相似文献
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降低运维成本是保障海上风电经济效益的关键,运维方案优化对降低海上风电机组运维成本和提高发电量起着双重作用。根据风电机组零部件的可靠度模型,计算出每台风电机组最佳维修时机对应的时间窗,考虑提前维修和故障后维修的经济损失,建立包含时间窗约束的海上风电机组运维方案优化模型,然后设计基于参数优化的改进遗传算法计算出最优运维方案。最后采用某海上风电场内风电机组运维案例验证模型和算法,结果表明考虑时间窗约束的运维方案可大幅度提高海上风电的经济效益,改进遗传算法比传统遗传算法具有更强的寻优能力。 相似文献
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虽然我国第一台海上风电机组并非安装在潮间带地区,但在经历了5年左右的发展后,潮间带风电项目在我国海上风电项目中占据了主流地位。因此,若想对我国海上风电发展有一个清晰的认识,对潮间带风电的了解显得非常重要。 相似文献
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Korea has huge potential for offshore wind energy and the first Korean offshore wind farm has been initiated off the southwest coast. With increasing water depth, different substructures of the offshore wind turbine, such as the jacket and multipile, are the increasing focus of attention because they appear to be cost-effective. However, these substructures are still in the early stages of development in the offshore wind industry. The aim of the present study was to design a suitable substructure, such as a jacket or multipile, to support a 5 MW wind turbine in 33 m deep water for the Korean Southwest Offshore Wind Farm. This study also aimed to compare the dynamic responses of different substructures including the monopile, jacket and multipile and evaluate their feasibility. We therefore performed an eigenanalysis and a coupled aero-hydro-servo-elastic simulation under deterministic and stochastic conditions in the environmental conditions in Korea. The results showed that the designed jacket and multipile substructures, together with the modified monopile, were well located at soft–stiff intervals, where most modern utility-scale wind turbine support structures are designed. The dynamic responses of the different substructures showed that of the three substructures, the performance of the jacket was very good. In addition, considering the simple configuration of the multipile, which results in lower manufacturing cost, this substructure can provide another possible solution for Korean’s first offshore wind farm. This study provides knowledge that can be applied for the deployment of large-scale offshore wind turbines in intermediate water depths in Korea. 相似文献
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A probabilistic formulation is proposed to assess the performance of the support structure of offshore wind turbines based on their probability and expected time of exceeding specified drift thresholds. To this end, novel probabilistic models are developed to predict the mean and standard deviation of the drift ratio response of wind turbine support structures operating under day-to-day loads as a function of the wind turbine geometry and material properties, and loading conditions. The proposed models are assessed using a database of virtual experiments generated using detailed three-dimensional (3D) nonlinear finite element (FE) models of a set of representative wind turbine configurations. The developed models are then used in a random vibration formulation to estimate the probability and expected time of exceeding specified drift thresholds. As an example, the probability and expected time of exceeding specified drift thresholds are estimated for a typical offshore wind turbine at different wind speeds. A comparison is made between the results obtained based on the proposed models, those obtained using simulators commonly used in practice and detailed 3D nonlinear FE analyses. 相似文献
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S. N. Voormeeren P. L. C. van der Valk B. P. Nortier D‐P. Molenaar D. J. Rixen 《风能》2014,17(7):1035-1054
Traditionally, wind turbine dynamics are analyzed using computationally efficient but geometrically coarse aeroelastic models. With ever larger offshore turbines being installed in deeper waters, the wind industry is gradually moving toward more complex foundation types such as jackets and tripods. Even the simplest models of such structures have many more degrees of freedom (DoFs) than the complete wind turbine model, leading to excessive computation times. To cope with this, we can employ reduced ‘superelement’ modeling of the support structure. However, since these structures are subjected to hydrodynamic loading at a large portion of their DoFs, traditional reduction methods fail to properly describe the response to this excitation. In this paper, we therefore propose to combine superelement modeling with the concept of modal truncation augmentation, which consists in extending the reduction basis by adding ‘residual vectors’. Furthermore, we use principal component analysis to find the predominant hydrodynamic loading on the support structure. A case study is performed on a reference wind turbine model on a jacket structure, revealing both the need for coupled dynamic analysis and the shortcomings of traditional superelement models for offshore support structures. Most importantly, this case study shows that the proposed augmented superelement approach allows to create very compact yet accurate models of the complex support structure, thereby enabling efficient integrated simulation of offshore wind turbines.Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Scenario analysis for techno‐economic model development of U.S. offshore wind support structures 下载免费PDF全文
Challenging bathymetry and soil conditions of future US offshore wind power plants might promote the use of multimember, fixed‐bottom structures (or ‘jackets’) in place of monopiles. Support structures affect costs associated with the balance of system and operation and maintenance. Understanding the link between these costs and the main environmental design drivers is crucial in the quest for a lower levelized cost of energy, and it is the main rationale for this work. Actual cost and engineering data are still scarce; hence, we evaluated a simplified engineering approach to tie key site and turbine parameters (e.g. water depth, wave height, tower‐head mass, hub height and generator rating) to the overall support weight. A jacket‐and‐tower sizing tool, part of the National Renewable Energy Laboratory's system engineering software suite, was utilized to achieve mass‐optimized support structures for 81 different configurations. This tool set provides preliminary sizing of all jacket components. Results showed reasonable agreement with the available industry data, and that the jacket mass is mainly driven by water depth, but hub height and tower‐head mass become more influential at greater turbine ratings. A larger sensitivity of the structural mass to wave height and target eigenfrequency was observed for the deepest water conditions (>40 m). Thus, techno‐economic analyses using this model should be based on accurate estimates of actual metocean conditions and turbine parameters especially for deep waters. The relationships derived from this study will inform National Renewable Energy Laboratory's offshore balance of system cost model, and they will be used to evaluate the impact of changes in technology on offshore wind lower levelized cost of energy. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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The estimation of fatigue lifetime for an offshore wind turbine support structure requires a large number of time‐domain simulations. It is an important question whether it is possible to reduce the number of load cases while retaining a high level of accuracy of the results. We present a novel method for simplified fatigue load assessments based on statistical regression models that estimate fatigue damage during power production. The main idea is to predict the total fatigue damage only and not also the individual damage values for each load case. We demonstrate the method for a jacket‐type support structure. Reducing the number of simulated load cases from 21 to 3, the total fatigue damage estimate exhibited a maximum error of about 6% compared with the complete assessment. As a consequence, a significant amount of simulation time can be saved, in the order of a factor of seven. This quick fatigue assessment is especially interesting in the application of structural optimization, with a large number of iterations. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献