【作者】 李飞；

【导师】 金鑫；

【作者基本信息】 重庆大学 ， 工程（机械工程）（专业学位）， 2022， 硕士

【摘要】 随着风电技术的不断发展,固定式海上风机在近海海域的可发展面积不断接近饱和,为了捕获更丰富的海上风资源,在超过50m水深的海域,海上漂浮式风电机组将是比固定式更经济可行的选择。长期工作在复杂多变的恶劣海洋环境中,机组结构更容易受到极端风浪联合激励的影响,造成机身频繁振动,甚至导致结构破坏,严重影响风电机组的安全。为了降低海上漂浮式风电机组在遭受极端风浪联合激励下引起的结构振动和受载情况,提高其运行可靠性,有必要建立整机动力学模型,对海上漂浮式风力发电机组结构振动控制进行研究。本文主要内容为:(1)分析了海上漂浮式风力发电机组的基本结构组成,根据各结构间相对铰接关系,构建整机系统拓扑关系图;基于Euler-Bernoulli梁建立了含柔性叶片和塔筒的海上漂浮式风力发电机组整机系统多体动力学模型,对整机模态进行求解,得到各阶固有频率和模态振型。(2)对柔性体结构在极端阵风作用下的受载情况以及机组在极端风浪载荷作用下的动态响应进行了分析,结果表明:极端运行阵风主要影响叶根和塔底纵向弯矩,极端方向变化阵风主要影响塔底侧向弯矩;在极端风浪联合作用下,引起机组结构振动的主要响应频率对应平台纵摇频率。(3)基于极端外部环境载荷影响,研究了不同强度极端风浪联合激励下调谐质量阻尼器(Tuned Mass Damper,TMD)对整机振幅和结构受载抑制效果,结果表明:在风机运行状态下,随着外部环境载荷激励强度的增加,TMD对结构振动抑制率明显提高,对平台纵摇标准差抑制率最高达到43.5%;在风机泊机状态下,TMD也能有效降低极端环境载荷对机组的影响。(4)考虑了机组易发生的结构故障,研究了变桨机构发生故障卡死时,TMD在机组故障发电和故障停机过程对振动控制的影响,结果表明:在机组故障状态下,TMD依然能起到较好的控制效果,特别是在故障停机状态下对平台纵摇标准差抑制率达到62.8%。更多还原

【Abstract】 With the continuous development of wind power technology,the development area of fixed offshore wind turbines in offshore waters continues to be close to saturation.In order to capture more abundant offshore wind resources,floating offshore wind turbines will be more economical and feasible than fixed ones in the waters above 50 m depth.Long-term work in the complex and volatile harsh marine environment,the unit structure is more vulnerable to extreme wind and wave combined excitation,resulting in frequent vibration of the fuselage,and even lead to structural damage,seriously affecting the safety of wind turbines.In order to reduce the structural vibration and load of offshore floating wind turbine under extreme wind and wave combined excitation and improve its operation reliability,it is necessary to establish the dynamic model of the whole machine system to study the structural vibration control of offshore floating wind turbine.The main research contents of the thesis are as follows:(1)The basic structure of offshore floating wind turbine is analyzed,and the topology diagram of the whole system is constructed according to the relative hinge relationship between the structures.Based on Euler-Bernoulli beam,a multi-body dynamic model of the whole offshore floating wind turbine system with flexible blades and towers is established.The modal of the whole system is solved,and the natural frequencies and modal shapes of each order are obtained.(2)The load of flexible structure under extreme gust and the dynamic response of unit under extreme wind and wave loads are analyzed.The results show that the extreme operation gust mainly affects the longitudinal bending moment of blade root and tower bottom,and the extreme direction change gust mainly affects the lateral bending moment of tower bottom.Under the combined action of extreme wind and wave,the main response frequency that causes the vibration of unit structure corresponds to the platform pitch frequency.(3)Based on the influence of extreme external environment load,the inhibitory effect of TMD on the amplitude and structural load of the whole machine under the combined excitation of extreme wind and wave with different intensities was studied.The results show that under the condition of fan operation,with the increase of external environment load excitation intensity,the vibration inhibition rate of TMD on the structure is obviously improved,and the standard deviation inhibition rate of platform pitch is up to 43.5%.TMD can also effectively reduce the influence of extreme environmental load on the unit under the condition of wind turbine.(4)Considering the structural failure of the unit,the influence of TMD on the vibration control of the unit in the process of fault power generation and fault shutdown is studied when the fault of the pitch mechanism is stuck.The results show that the TMD can still play a good control effect in the fault state of the unit,especially in the fault shutdown state,the inhibition rate of the standard deviation of the platform pitch is 62.8%.更多还原