海上漂浮式风电机组结构载荷与运动特性建模与分析

发布时间：2019-01-06 07:59

【摘要】：从近年来风电产业发展态势来看,剩余可开发陆地风电场日益减少,海上风电场的开发是必然趋势;考虑近海渔业、军事等实际条件限制,深海漂浮式风力发电机组的开发具有重要意义。早在1972年,Massachusetts大学的Heronemus教授就提出了深海漂浮式风力发电机组设计理念。与陆地和近海风力发电机组不同,海上漂浮式风力发电机组无固定底座,采用的漂浮式平台具有六自由度。然而,在复杂的服役环境下,海上漂浮式风电机组的载荷和运动特性都更复杂,不仅需要承受风载荷,还需要承受复杂的波浪载荷,这限制了海上漂浮式风电机组目前的实际应用。为此,本文以三浮桶支撑结构的海上漂浮式风电机为研究对象,从“叶片载荷与运动分析—漂浮平台设计—漂浮式平台载荷与运动分析”这一主线展开相关研究工作,旨在厘清海上漂浮式风电机组结构载荷建模与运动特性分析方法。本文的主要研究工作和创新如下:(1)构建了计及叶片柔性的载荷与运动特性建模方法。该方法将整个叶片划分为若干个单元,单元之间采用弹性铰模型,模型的精确程度可以通过叶片单元数进行控制。为便于分析,通过建立机舱坐标系,叶片坐标系,转轴坐标系等坐标系对风电机组叶片的载荷进行分析。在Matlab/Simulink环境下,构建了叶片惯性载荷计算仿真模型,离心力载荷仿真模型,重力载荷仿真模型和气动载荷仿真模型。通过对风电机组叶片载荷及运动特性进行数值仿真分析,基本掌握了其载荷与运动特性。(2)联合考虑了风波之间的关联特性,借助风电机组空气动力学理论和波浪力学理论构建风波载荷计算模型。讨论了极限服役条件下风电机组三种典型受力模型,并以此为依据作为参数设计的基准。分析时当压水舱的直径与波长的比值DT/L0小于0.2视为小尺度结构,引入Morison方程进行载荷分析;当压水舱的直径与波长的比值DT/L0大于0.2视为大尺度结构,引入MacCamy-Fuchs公式进行载荷分析。(3)分析并建立了海上漂浮式风电机组在运行过程中承受的风载荷、波浪载荷、重力载荷等多重载荷模型,将运动过程划分为平动和转动的组合,并采用递进迭代求解的方式进行综合求解。最后在Simulink环境下将输入风模型、叶片(风轮)模型、漂浮式平台模型等多个子模型集成于风电机组整机仿真平台中,并进行数值仿真分析。仿真结果能够有效分析漂浮式风电机组运行载荷和运动特性,有助于理解其运行机理,为设计和控制提供参考。
[Abstract]:According to the development situation of wind power industry in recent years, the remaining exploitable land wind farm is decreasing day by day, and the development of offshore wind farm is an inevitable trend. The development of deep sea floating wind turbine is of great significance considering the actual conditions of offshore fishing and military. As early as 1972, Professor Heronemus of Massachusetts University proposed the design concept of deep-sea floating wind turbines. Unlike land and offshore wind turbines, offshore floating wind turbines have no fixed base, and the floating platform has six degrees of freedom. However, in the complex service environment, the load and motion characteristics of the floating wind turbine are more complex, which requires not only the wind load, but also the complex wave load. This limits the practical application of floating wind turbine. Therefore, this paper takes the floating wind motor with three floating bucket support structure as the research object, from the main line of "blade load and motion analysis-floating platform design-floating platform load and motion analysis" the related research work is carried out. The purpose of this paper is to clarify the method of structural load modeling and motion characteristic analysis of floating wind turbine. The main work and innovations of this paper are as follows: (1) the modeling method of load and motion characteristics considering blade flexibility is constructed. In this method, the whole blade is divided into several elements, and the elastic hinge model is used among the elements. The accuracy of the model can be controlled by the number of blade units. In order to facilitate the analysis, the load of wind turbine blade is analyzed by establishing the coordinate system of engine room, blade coordinate system, rotating axis coordinate system and so on. In the environment of Matlab/Simulink, the simulation models of inertia load, centrifugal force load, gravity load and aerodynamic load are constructed. Through the numerical simulation and analysis of the load and motion characteristics of wind turbine blades, the load and motion characteristics of wind turbine blades are basically grasped. (2) the correlation characteristics of wind waves are considered jointly. The wind wave load calculation model is constructed with the help of wind turbine aerodynamics theory and wave mechanics theory. This paper discusses three typical force models of wind turbine under the condition of limited service and takes them as the basis of parameter design. When the ratio of diameter to wavelength of the pressurized tank (DT/L0) is less than 0. 2 as a small scale structure, the Morison equation is introduced to analyze the load. When the ratio of diameter to wavelength of pressurized water tank (DT/L0) is more than 0. 2 as a large scale structure, the MacCamy-Fuchs formula is introduced to analyze the load. (3) the wind load of floating wind turbine is analyzed and established. The motion process is divided into the combination of translation and rotation in the model of multiple loads such as wave load and gravity load. The method of progressive iterative solution is used to solve the motion process synthetically. Finally, several sub-models, such as input wind model, blade (wind turbine) model, floating platform model and so on, are integrated into the wind turbine simulation platform under Simulink environment, and the numerical simulation analysis is carried out. The simulation results can effectively analyze the operating load and motion characteristics of floating wind turbine, help to understand its operation mechanism, and provide reference for design and control.
【学位授予单位】：湖南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM315

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