倾斜工况风力发电机振动特性变化规律及振动抑制研究

Vibration is an important indicator to measure the quality and performance of the wind power generator. The dynamic design and manufacturing are often conducted according to the horizontal working condition at present. Due to the particularity of high altitude working environment and installed obliquely in the flexible tower through the elastic supports, the generator vibration is obvious under tilting installation condition and seriously restricts the quality and operation maintenance of the products. In order to reveal the rules between the generator vibration excitation source characteristics and tilting angle, the project investigates the generator rotor unbalance, electromagnetic force and the incentive characteristics of the bearing started from analyzing the vibration reasons of generator under the tilting working condition; The dynamic equations of vibration transmission are established by using dynamic substructure analysis method under tilting working condition. The generator vibration transmission characteristics are investigated for the system structure parameters, vibration isolator and the dynamic characteristics of connection interfaces under tilting working condition by using power flow method to reveal the rule between the vibration excitation characteristics and the generator tilting angle. Under the tilting working condition, the system dynamic model of generator-isolator-rack is built. The response characteristics of generator excitation source and system vibration transmission path are investigated to reveal the rule between the generator vibration response characteristics and the tilting angle. Finally, the corresponding optimization methods are put forward between the vibration excitation source control and system dynamics parameters. The research provides theoretical foundation and technical supports for the dynamic design, manufacturing and operation maintenance of the wind power generators.

振动是衡量风力发电机质量和性能的重要指标，目前均按水平工况进行发电机动力学设计和生产制造，由于高空工作环境和通过弹性支承倾斜安装于柔性塔筒的特殊性，导致倾斜工况下振动问题非常突出，严重制约产品性能和运行管理。项目拟从分析倾斜工况发电机振动原因入手，研究发电机转子不平衡、电磁力和轴承局部缺陷等激振机理与特性，揭示发电机激振源特性与倾斜角度的变化规律；基于动态子结构法，推导倾斜工况发电机系统振动传递动力学方程，结合功率流法，分析系统结构参数、隔振器和连接界面动力特性对发电机振动传递影响，揭示倾斜工况发电机振动传递变化规律；构建倾斜工况发电机-隔振器-机架系统动力学模型，研究发电机激振源和传递路径对系统振动的响应特性，揭示倾斜工况发电机振动响应变化规律；基于此，提出相应的激振源控制与系统动力学参数优化方法。项目研究成果可为风力发电机等旋转机械动力学设计、生产制造和运行维护提供理论依据和技术支撑。

项目通过研究倾斜工况风力发电机振动特性变化规律及振动抑制方法，在转子动力学建模、不平衡振动特性、动平衡与振动控制方法等方面取得了一些重要进展。(1)风力发电机转子动力学建模与振动机理研究。针对1.5MW双馈风力发电机转子参数，构建了发电机转子动力学模型，分析了临界转速与模态振型。研究了轴承、减震垫缺陷下振动特性。(2)研究风力发电机零部件与整机结构振动关联特性。得出电机底板、定子绕组、转轴、铁芯、前端盖及后端盖零部件对整机前三阶模态的贡献程度依次增大。研究揭示出倾斜安装工况电机基础螺栓松动振动特性。(3)设计了一种倾斜安装角度可调的风力发电机动力学特性模拟实验装置，开展电机转子轴系稳态不平衡响应分析，总结了不同轴向位置、幅值大小和相位差下轴系不平衡振动响应变化规律。(4)提出轴系整机无试重虚拟动平衡法、旋转机械多平面多测点多转速轴系影响系数动平衡法，各支承平均降幅约为25%，单点降幅最高可达到50%。(5)提出基于入口油温调节和电磁轴承的转子振动特性控制研究，通过改变支承动力特性来控制转子的振动。(6)提出基于加工精度优化的转子不平衡振动抑制方法。构建出加工精度模型，发现在100rpm转速下，转轴同轴度和永磁体安装槽对称度加工精度影响最大。项目研究可为旋转机械动力学设计、生产制造和运行维护提供理论参考。项目组已在国内外期刊和国际会议上发表学术论文27篇，其中SCI 源刊5篇，EI 收录10篇次；申请国家发明专利5项，获授权发明专利10项；“大型转子机械早期故障特征识别与不平衡振动抑制规律”获2018年湖南省自然科学二等奖、“透平压缩机组高稳定性设计与自愈调控关键技术及工程应用”获2019年中国石油和化学工业联合会科学技术一等奖、“高速柔性多转子轴系无试重动平衡检测与控制技术”获2017年中国仪器仪表学会科学技术奖三等奖各1项；进行国内外学术交流26人次；正在培养博士研究生2名、硕士研究生8名，毕业博士研究生1名、硕士研究生5人。完成了项目计划工作和任务。