风电机组传动系统动力学认证分析

本文通过分析风电机组传动系统动力学相关知识以及国内外相关研究,介绍了为进行传动系统动力学分析技术研发所开展的两个科学研究和项目示范,最终在顺利完成科研课题的基础上,摸索出一套风电机组传动系统动力学分析的流程,并制定了相关的指导规范。     

基于温度归一化的风电机组发电量模型研究

针对环境温度影响风电机组的输出功率及发电量计算的问题,通过分析风速的分布建立威布尔分布模型;分析温度对风电机组输出功率的影响,推导出温度归一化的功率折算公式,将功率折算到统一基准温度下,提出基于温度归一化的风电机组发电量计算模型。以新疆某风电场为算例,分别计算出4台风电机组的发电量,将温度归一化模型和传统算法计算的发电量与实测SCADA数据进行对比,验证温度归一化模型计算发电量的精确性。     

大型风电机组地震载荷计算方法优化

通过对比传统建筑物与风电机组的特性差异,提出需要考虑风电机组特性的模态振型分析方法及结合风电机组受载特性,修正地震效应的叠加方法。基于此方法对某2.0 MW风电机组进行地震载荷动力学分析,分析数据同风电机组权威软件GH Bladed 4.2数据比较表明,该分析方法可较好地计算风电机组的地震载荷,从而可为简化地震载荷计算流程提供有力技术支撑。     

基于多体动力学的双馈式风机复合主轴传动链建模与仿真分析

文章设计了风电机组的复合主轴,采用了柔性多体动力学理论对风电机组传动链进行高精度建模,建立了风电机组传动链系统拓扑结构和动力学微分方程组,构建了风电机组传动链系统的动力学数学模型,通过时域瞬态动力学分析研究各部件的力、速度、加速度等的响应,揭示了传动链的模态、阶次和共振特性。基于柔性多体动力学平台建立了风电机组传动链高精度仿真模型,对传动链的激励频率及固有频率进行模拟分析,并与通用软件计算结果及实测数据进行了对比验证。验证结果表明,柔性多体动力学仿真结果与通用软件计算结果的仿真载荷时序曲线趋势一致,且载荷均值、幅值比较一致,与动态频率的实测结果平均相差1.51%。同时设计了复合主轴,编写复合材料主轴优化程序,与传统主轴相比,重量轻、刚度更好,优化后的传动链位移、速度、加速度、载荷的极限值分别降低了1.0%,42.7%,13.8%和2.1%,表明了系统更加稳定。     

基于随机组合赋权模糊评价的风电机组健康状态评估

由于健康指标权重随机性会导致风电机组状态评估灵敏度降低,提出一种评估风电机组健康状态的随机组合赋权模糊评价方法。首先,通过相关性、方差、偏度等多角度分析风电场采集与监视控制系统（SCADA）数据,结合IEC61400-1标准建立机组健康状态评估指标架构,并基于随机因子优化组合权重得到赋权公式,提高评估指标层权重的准确性。其次,为充分覆盖评估指标数据劣化度,基于岭型分布函数建立健康指标劣化隶属度计算函数。结合随机组合权重和隶属度函数,构建风电机组健康状态模糊综合评价数学模型。通过分层评估风电机组健康状态指标架构,得到机组健康等级并实现故障预警。最后,对大连驼山风电场多台机组进行评估试验,结果表明：该文方法能准确评估出风电机组健康状态等级,相比组合赋权云模型方法,灵敏度提高了1.85%。     

基于数字孪生技术的风电机组建模研究

针对以往风电机组数字孪生建模受不同研究目的或单一软件的功能限制，难以建立风电机组整机模型的问题，提出一种新的风电机组孪生建模方法。该方法首先依托FAST风速性能模块，建立稳态风模型、随机湍流风模型以及风电场实时风速模型；接着采用空气动力学模块和结构动力学模块分别搭建风电机组叶片、塔架等关键部件的几何与动力学模型；最后在Simulink中搭建风电机组电气系统模型及控制策略，由此构建完整的风电机组孪生模型。将该孪生建模方法分别用于WindPACT 1.5 MW双馈风电机组与某风电场Fuhrl?nder 2.5 MW双馈风电机组并进行验证。结果表明：孪生模型在不同风速模型下，各重要生产参数相比设计标准及实际运行数据均具有较高的准确性。此外，通过对风电机组数字孪生系统实时仿真和现场不可测数据的孪生模拟，也进一步表明孪生模型具有可行性和有效性。     

XGBoost算法在风电机组发电机故障监测预警中的应用研究

发电机作为整个风电机组的核心部件之一,其能否正常运行将严重影响风电机组的持续发电。利用集成机器学习算法中的梯度提升算法XGBoost对风电机组发电机故障监测预警进行研究。首先,提取数据采集与监控(SCADA)系统数据库中风电机组在并网状态下的正常运行大数据,对缺失、异常数据进行预处理后,结合运维专家经验利用XGBoost算法筛选出关键特征变量;然后经过训练和参数调整,建立最优风电机组发电机故障监测预警模型;通过对照研究发现,XGBoost算法对风电机组发电机进行故障监测预警的效果优于随机森林算法和Cat Boost算法;最后利用关键特征变量重要性排序作为风电机组发电机故障诊断与定位的参考。     

风力发电系统发电容量时间序列的混沌属性分析

利用非线性动力学的分析方法对并网型风电机组的发电容量时间序列进行分析,以检验其是否存在混沌属性。分析表明,通过对低维非线性动力学建模,风电机组发电容量时间序列表现出了混沌特性,此结果为基于混沌时间序列的风力发电容量预测奠定了基础。     

基于数据融合的风电变桨系统故障预警研究

随着风电机组装机容量的不断攀升,同时带来并网发电率低、机组故障率高等缺点,导致风电机组整体利用率较低。为此提出一种基于数据融合的风电变桨系统故障预警方法。首先结合SCADA系统中的运行统计信息和历史数据,采用Relief特征参数选择方法筛选出与风电变桨系统故障相关的特征参数;然后采用数据融合的方法,建立基于MSET技术的风电变桨系统故障预测模型,并采用滑动窗口法进行故障预警阈值的确定;最后以上海某风场1.5 MW双馈异步风电机组进行实例分析,结果表明该方法可提前发现风电变桨系统故障征兆,实现对风电变桨系统的早期故障预警。     

1.5兆瓦风电机组安全性故障分析与处理

风电机组安全问题是一个重大课题,在机组倒塌或烧毁后,现场将受到严重破坏,仅凭个别数据很难分析出事故具体原因。本文就制造、调试、运行和维护过程中出现的风电机组安全性故障进行分析,重点排除安全隐患,消除安全性故障,防止风电机组重大安     

风力机地震动力学研究现状综述

针对风力机地震问题研究,从地震反应谱频域分析法、有限元高精度结构动力学分析法、考虑风与地震耦合动力学分析法和结构抗震控制四方面详细阐述了近二十年各国学者的相关研究成果,讨论了不同计算方法发展历程及其优缺点,分析了风力机地震动力学方面研究的不足,并提出了未来的研究重点领域及发展方向。     

大型海上风力机地震冲击角动力学响应分析

为研究海上风力机在不同地震冲击角下的动力学响应,基于p-y曲线法构建土-构耦合模型,基于DTU 10 MW 单桩式近海风力机建立有限元模型,研究地震冲击角变化对大型海上风力机地震动力学响应的影响。结果表明：0°和90°地震冲击角下风力机结构受载荷响应最剧烈;当地震冲击角为锐角时,塔顶前后向和侧向位移幅值均下降,总应变能集聚现象显著缓解;地震冲击角为15°和30°时风力机等效应力均值相对其他角度有明显下降。因此,主动调整风力机叶轮朝向以调整地震冲击角可能成为风力机受地震冲击后降低损害的有效控制方式。     

大型风力机地震动力响应研究

为研究地震载荷与风载荷联合作用下的大型风力机结构动力学响应,本文研究分别以Wind PACT 1.5 MW和NREL 5 MW风力机为研究对象,采用EI Centro 6.9级地震为输入激励,通过改进版的开源软件FAST(风电载荷仿真软件)计算风力机在正常运行、紧急停机和一直停机3种运行方式下的塔顶振动和塔架结构荷载情况,结果表明:地震载荷极大加剧了塔顶振动,机舱加速度峰值增大2倍以上。紧急停机操作可减小塔尖位移,一定程度上可以保护风力机结构安全。地震载荷主要增大了塔架一阶固有频率及其二倍频的振动。6.9级地震与额定风载荷联合作用下,NREL 5MW风力机塔基弯矩设计需求为159 MN·m,略大于极限风载荷作用。说明地震常发地区,塔架结构强度设计必须考虑地震载荷作用。     

Wind turbines and seismic hazard: a state‐of‐the‐art review

Wind energy is a rapidly growing field of renewable energy, and as such, intensive scientific and societal interest has been already attracted. Research on wind turbine structures has been mostly focused on the structural analysis, design and/or assessment of wind turbines mainly against normal (environmental) exposures while, so far, only marginal attention has been spent on considering extreme natural hazards that threat the reliability of the lifetime‐oriented wind turbine's performance. Especially, recent installations of numerous wind turbines in earthquake prone areas worldwide (e.g., China, USA, India, Southern Europe and East Asia) highlight the necessity for thorough consideration of the seismic implications on these energy harnessing systems. Along these lines, this state‐of‐the‐art paper presents a comparative survey of the published research relevant to the seismic analysis, design and assessment of wind turbines. Based on numerical simulation, either deterministic or probabilistic approaches are reviewed, because they have been adopted to investigate the sensitivity of wind turbines' structural capacity and reliability in earthquake‐induced loading. The relevance of seismic hazard for wind turbines is further enlightened by available experimental studies, being also comprehensively reported through this paper. The main contribution of the study presented herein is to identify the key factors for wind turbines' seismic performance, while important milestones for ongoing and future advancement are emphasized. Copyright © 2016 John Wiley & Sons, Ltd.     

不同海况及伺服系统作用下10 MW单桩式风力机地震易损性研究

为探究不同海况及伺服系统下单桩式近海风力机的地震易损性,以DTU 10 MW风力机为研究对象,建立风浪相关的地震-湍流风-波浪多物理场模型,研究其在变速变桨伺服系统下的动力特性,基于增量动力分析方法评估其地震易损性。结果表明：变速变桨伺服系统可有效缓解风力机高风速下无地震作用时的塔顶振动;当风轮在大推力下,较小的波浪载荷一定程度上可降低风力机塔顶振动及塔底弯矩;随地震动强度增加,风力机各临界损伤状态失效概率逐渐增加;风力机地震易损性主要由地震动强度决定,波浪载荷与湍流风载荷对风力机地震易损性影响较小。     

考虑冲刷的单桩式海上风力机动力响应研究

为了研究复杂海洋环境下桩周冲刷对海上风力机动力响应的影响,以美国可再生能源实验室5 MW海上风力机为研究对象,建立风力机塔架-单桩-土体有限元模型,计入风浪和地震荷载对冲刷情况下的单桩式海上风力机进行动力响应研究。对比分析不同冲刷深度以及冲刷坡角对风力机系统固有频率和动力响应的影响。研究表明：当冲刷深度增加到二倍桩径时,风力机一阶固有频率降低至转子1P频率附近,容易引起共振;在风浪荷载以及风浪、地震联合荷载作用下,冲刷坡角不变,风力机最大位移与弯矩随着冲刷深度增加而增大,疏松土质条件下的增量大于紧密土;保持冲刷深度不变,冲刷坡角的变化对风力机动力响应影响较小。     

钢-混凝土组合式风力发电塔架地震响应分析

钢-混凝土组合式风力发电塔架上部为钢塔筒,下部为混凝土塔筒,高度方向具有较大的质量和刚度突变,其在地震作用下的响应和传统单管式钢塔架显著不同.利用ABAQUS对同一风电场的2.0 MW单管式钢塔架和组合式塔架建立精细化模型,选取3种场地条件,采用振型分解反应谱法计算2种塔架的地震响应并进行对比.针对3种场地条件,选取相...     

Assessing the seismic wavefield of a wind turbine using polarization analysis

Ambient seismic noise can often be seen as problematic but with the right analysis can act as a tool to image the Earth. Wind turbines are known to generate low frequency vibrations; however, the wave types that are generated are currently unknown. Characterizing these vibrations will allow wind turbines to be used as a seismic source and be of value to geotechnical applications and seismic interferometry. This paper uses polarization analysis of the seismic wavefield around a small wind turbine to identify the type of wave being generated by the turbine and to clarify the source. The seismic data recorded 190 m from the wind turbine are processed using a window length of 0.1 s and bandpass filtered on a selection of frequency ranges. Polarization analysis is performed for two different wind speed ranges, in order to show the variation of wave characteristics between operational and non‐operational modes of the wind turbine. Polarized surface waves are identified as the predominant wave type at blade rotation harmonics, making this work particularly relevant to multichannel analysis of surface waves and seismic interferometry. Copyright © 2017 John Wiley & Sons, Ltd.     

Blockage effects in wind farms

An experimental study of wind farm blockage has been performed to quantify the velocity decrease that the first row of a wind farm experiences due to the presence of the other turbines downstream. The general perception has been that turbines downstream of the first row are only influenced by the wakes from upstream turbines without any upstream effect. In the present study, an attempt is made to demonstrate the existence of a two‐way coupling between individual turbines and turbines in the wind farm. Several staggered layouts were tested in the wind tunnel experiments by changing the spacing between rows, spacing between turbines in the rows, and the amount of wind turbines involved. The experiments focused on turbines located in the center of the first row as well as the two turbines located in the row edges, usually believed to experience a speedup. The present results show that no speedup is present and that all the turbines in the first row are subjected to a reduced wind speed. This phenomenon has been considered to be due to “global blockage.” An empirical correlation formula between spacing, number of rows, and velocity decrease is proposed to quantify such effect for the center turbine as well as for the turbines at the edges.     

Modeling,simulation and control of a wind turbine with a hydraulic transmission system

A complete mathematical model of a hydraulic transmission concept for use in wind turbines is presented. The hydraulic system transfers the power from the nacelle to ground level. The main focus has been to develop a model that takes into account the most important dynamics affecting the wind turbine and the hydraulic transmission system involved, such that the model can be used to analyze the dynamic feasibility of a hydraulic transmission concept. Further, dynamic analysis of a hydraulic transmission system for wind turbines is investigated. The nonlinear dynamic model is developed in MATLAB Simulink. Analytical calculation of natural periods of a linearized model corresponds well with simulations of the overall system. A valve control system is proposed to reduce pressure and power fluctuations at operation both below and above the rated wind speed for the wind turbine. Further, a blade pitch control system based on an aerodynamic power estimator is proposed for operation above the rated wind speed. System simulations for one case below and one case above the rated wind speed show that the dynamic response of the overall system is stable and that the wind turbine variables are within typical ranges for conventional variable speed wind turbines with mechanical transmission. Copyright © 2012 John Wiley & Sons, Ltd.