兆瓦级风力发电机组动力学分析

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3.0 陈辉 2024-11-20 5 4 2.5MB 102 页 15积分
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摘 要
风力发电机组的动力学分析主要是研究系统的共振和稳定性问题，当风力发
电机组在自然风条件下运行时，由于作用在风力发电机组叶片上的空气动力、惯
性力和弹性力等交变载荷，就会使弹性振动体叶片和塔架产生耦合振动，如果外
界激振力的频率接近系统的固有频率时，系统就可能发生共振，共振时将对机组
产生强烈的破坏。因此，要排除共振，就要使系统的固有频率在一定范围内避开
外界激振力的频率。
本文针对现代大型水平轴风力机结构和运行特点、结合外部环境和风力机国
际标准，对全系统载荷计算方法进行了研究。以 1.5MW 变速恒频风力机为研究
对象，研究了风力机在气动和机械载荷作用下的动力学响应等问题。论文主要包
括五个部分：风力机全系统载荷分析和计算方法，风力机叶片三维实体建模及塔
架设计方法，Bladed 软件的动力学计算，叶片挥舞、塔架前后弯曲耦合振动情况
分析。
首先分析作用在风力机上的载荷，这些载荷主要是气动和机械载荷。气动性
能计算和载荷分析采用叶素-动量理论，该理论综合了动量理论和叶素理论，考虑
了叶尖损失、角效应、风轮实度、风剪和偏航效应等，能更准确计算风轮气动特
性。载荷分析为风力机后续分析设计奠定了基础。
第三章对风力机叶片三维建模进行了研究。探讨了叶片三维实体建模的通用
性方法及叶片几何参数设计的优化方法，为风力机结构有限元分析及模态分析打
下了基础。
第四章研究了风力机塔架设计方法。应用 ANSYS10.0 对1.5MW 风力机塔架
进行了稳定性分析。提出了机舱、风轮和地基的模拟方法，应用 ANSYS10.0 建
立了塔架-机舱-风轮-地基耦合模型，并计算了风力机塔架的振动模态。
文章最后对叶片挥舞、塔架前后弯曲耦合振动情况进行了分析，将不旋转的
塔架部分和旋转的风轮部分隔开进行研究，采用模态分析法分别建立了转子、轮
毂和机舱塔架的运动方程，然后利用轮毂和塔架的变形一致条件，将转子轮毂和
机舱塔架的运动方程耦合，建立了风轮转子/塔架系统的运动方程。
用所建的数学模型对 1.5MW 机型进行了分析和验证，得到了系统的固有频
率，结果显示没有与风轮的激励频率重合，并且从响应曲线上可以看出该机组是
稳定运行的。为了验证所建模型的正确性，利用 Bladed 风力发电机组专业设计软
件对该机型进行了分析和计算，两种方法的计算结果一致性好。
关键词：风力发电机组 叶素-动量理论 模态分析 共振
ABSTRACT
The primary problem of dynamic researching is the systematic resonance and
stability for the wind turbine. The alternate load, air driving force, inertial force and
elastic force etc that be pressed on the blade of wind turbine, can bring on coupling
vibration of the elastic blade and tower when the wind turbine works in the condition
of natural wind. If the frequency of outside force approaches the systematic natural
frequency, the resonance will be happened and arousing intense destroying for wind
turbine. Therefore, only making the systematic natural frequency keep away from the
frequency of outside force can avoid resonance.
Aimed at the configuration and operation characteristic of the modern large-scale
horizontal axis wind turbine, combining the external environment and the international
standards of wind turbine design, the load analysis method of the whole wind turbine
system is studied. The 1.5MW variable speed constant frequency wind turbine is taken
as investigation subject, the analysis method of the large-scale wind turbine dynamic
response caused by the aerodynamic load and mechanical load are investigated. In the
thesis, five parts are mainly included: system-load computing method of wind turbine,
blade's three-dimensional solid modeling and tower designing method, dynamic
computing of Bladed, the coupled rotor brandishing and tower front and back bending
system is analyzed.
Above all, the aerodynamic and mechanical loads applied on the wind turbine are
analyzed. The aerodynamic performance prediction and loading analysis are based on
the strip theory, synthesizing Moment and Blade Element theories and considering tip
loses, angle effects, solidity, wind shear, yawing effects, etc. The aerodynamic
characteristics of the rotor can be predicted accurately, and the work provides a
calculating base for the wind turbine's subsequent analysis and design.
In the chapter three, a study on the common methods used in wind blade's
three-dimensional modeling are discussed, optimal design of Blade Geometry
Parameters which can provide the basis for wind turbine's structure finite element
analysis.
In the chapter four, a method to design wind turbine tower is given. By using
ANSYS10.0, the stability analyses of 1.5MW wind turbine tower are carried out. An
analogy method for cabin, wind wheel and foundation is provided. Applying
ANSYS10.0, the tower-cabin-foundation coupling model is established and the wind
turbine tower vibration modality is analyzed.
In the last, the coupled rotor brandishing and tower front and back bending system
is analyzed. First, tower and rotor are separated, a motion equation is set up which
could describe rotor hub and nacelle tower with mode analytical method. Then, the
consistent condition of hub and tower is performed to establish the coupled rotor/tower
motion equation.
The 1.5MW wind turbine is analyzed with the above model. The systematic
natural frequency and response curve are obtained. The results indicate that the wind
work is steady and the systematic natural frequency is not coincided with the rotor
frequency. In order to prove the mathematical model is correct, the wind turbine is also
analyzed and calculated with Bladed wind turbine special design software, basically
consistent results are obtained.
Key Word: Wind Turbine, BEM, Model Analysis, Resonance
目 录
摘 要
ABSTRACT
第一章 引 言 ...................................................................................................................1
§1.1 国内外风电发展情况 .......................................................................................1
§1.1.1 世界风电发展情况 .................................................................................1
§1.1.2 我国风电发展情况 .................................................................................3
§1.2 风力发电技术的现状和发展趋势 ....................................................................5
§1.3 国内外风力发电机组动力学研究现状 ............................................................5
§1.3.1 国外风力发电机组动力学研究现状 ......................................................6
§1.3.2 国内风力发电机组动力学研究现状 ......................................................8
§1.4 动力学设计内容 ...............................................................................................8
§1.5 风力发电机设计软件现状 ...............................................................................9
§1.6 本课题的来源、意义及研究内容 .................................................................10
§1.6.1 课题的来源 ...........................................................................................10
§1.6.2 选题的意义 ...........................................................................................10
§1.6.3 课题主要研究内容 ...............................................................................10
第二章 载荷分析 ...........................................................................................................11
§2.1 风力发电机组的总体参数 ..............................................................................11
§2.2 致动盘概念 .....................................................................................................13
§2.2.1 动量理论 ...............................................................................................13
§2.2.2 风轮利用系数和贝兹（Betz）极限 ................................................... 14
§2.2.3 推力(轴向力)系数 ................................................................................15
§2.3 风轮的气动特性 ..............................................................................................15
§2.3.1 风轮几何参数 .......................................................................................16
§2.3.2 假设风轮尾流不旋转的气动特性 .......................................................16
§2.3.3 考虑风轮后尾流旋转的气动特性 .......................................................17
§2.4 载荷分类和来源 .............................................................................................20
§2.5 风力机主要载荷的计算方法 .........................................................................21
§2.5.1 叶素理论 ...............................................................................................21
§2.5.2 叶素-动量理论（BEM）.....................................................................22
§2.5.3 柱涡理论 ...............................................................................................24
§2.5.4 翼型的升力和阻力 ...............................................................................26
§2.5.5 风力机主要载荷的确定方法 ...............................................................30
第三章 风力发电机组叶片设计 ...................................................................................33
§3.1 叶片三维实体建模 ..........................................................................................33
§3.1.1 叶片几何参数 .......................................................................................34
§3.1.2 翼型数据 ...............................................................................................34
§3.1.3 坐标变换 ...............................................................................................36
§3.1.4 几何模型 ...............................................................................................38
§3.2 叶片翼型优化设计 .........................................................................................39
§3.2.1 基于叶素理论的转矩和功率的确定 ...................................................39
§3.2.2 湍流状态下叶素理论的修正 ...............................................................40
§3.2.3 变速风机叶片优化设计 .......................................................................41
§3.2.4 简化叶片设计 .......................................................................................44
§3.2.5 忽略阻力对叶片设计的影响 ...............................................................45
第四章 风力发电机组塔架设计 ...................................................................................49
§4.1 风力发电机组塔架的主要设计内容 ..............................................................49
§4.2 塔架的动力学分析 ..........................................................................................50
§4.2.1 动力学中的有限元方法 .......................................................................50
§4.2.2 塔架模态分析 .......................................................................................52
第五章 基于 Bladed 软件的动态计算 ......................................................................... 61
§5.1 风力机载荷计算过程 .....................................................................................61
§5.2 坐标系的确定 .................................................................................................61
§5.3 工况的制定 .....................................................................................................62
§5.3.1 外界条件 ...............................................................................................63
§5.3.2 风力机发电机组的运行状态 ...............................................................63
§5.3.3 控制和保护系统 ...................................................................................63
§5.3.4 风力机国际标准 ...................................................................................64
§5.3.5 制定计算工况 .......................................................................................64
§5.4 Bladed 软件动态计算 ..................................................................................... 65
§5.4.1 模型的建立 ...........................................................................................66
§5.4.2 计算结果 ...............................................................................................68
第六章 叶片/塔架耦合系统动力学分析 ..................................................................... 71
§6.1 坐标系的建立 ..................................................................................................71
§6.2 模型的建立 ......................................................................................................74
§6.2.1 叶片轮毂的运动方程 ............................................................................74
§6.2.2 机舱塔架的运动方程 ............................................................................80
§6.2.3 风轮转子/塔架系统的耦合方程 .......................................................... 81
§6.4 风轮转子/塔架系统的固有频率及响应 ........................................................ 83
§6.4.1 叶片等效刚度和塔架等效半径的选取 ................................................83
§6.4.2 系统固有频率的求解 ............................................................................85
§6.4.3 系统响应的求解 ....................................................................................87
§6.4.4 系统的稳定性分析 ................................................................................89
第七章 结论与展望 .......................................................................................................91
§7.1 结论 .................................................................................................................91
§7.2 工作展望 .........................................................................................................92
参考文献 .........................................................................................................................93
在读期间公开发表的论文和承担科研项目及取得成果 .............................................97
致 谢 .............................................................................................................................99
摘要：

摘要风力发电机组的动力学分析主要是研究系统的共振和稳定性问题，当风力发电机组在自然风条件下运行时，由于作用在风力发电机组叶片上的空气动力、惯性力和弹性力等交变载荷，就会使弹性振动体叶片和塔架产生耦合振动，如果外界激振力的频率接近系统的固有频率时，系统就可能发生共振，共振时将对机组产生强烈的破坏。因此，要排除共振，就要使系统的固有频率在一定范围内避开外界激振力的频率。本文针对现代大型水平轴风力机结构和运行特点、结合外部环境和风力机国际标准，对全系统载荷计算方法进行了研究。以1.5MW变速恒频风力机为研究对象，研究了风力机在气动和机械载荷作用下的动力学响应等问题。论文主要包括五个部分：风力机全系统...

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作者：陈辉 分类：高等教育资料 价格：15积分 属性：102 页 大小：2.5MB 格式：PDF 时间：2024-11-20

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