大型风力发电机高速轴承动力学建模与故障诊断方法研究

The coupling mechanism between the intermittent working conditions and multi-source excitations, such as random wind loads, misalignment of the high-speed shaft, torsional vibration and bearing skidding, is one of the failure reasons for the pits in the high-speed bearings of large wind turbines. A clear understanding of the excitation mechanism, vibration characteristics and signal detection method can directly affect the accuracy and reliability of the condition monitoring of the high-speed bearings. In this work, the high-speed bearings with pits in the large wind turbines are applied to investigate the pits mechanism, vibration characteristics and fault feature extraction and detection. The details of this works are listed as follows: (1) the excitation mechanism of the pits in the high-speed bearings considering the coupling between the misalignment and bending deflection of the high-speed shaft is studied to establish the relationship between the types of the pits and the coupling between the misalignment and bending deflection of the high-speed shaft. (2) A dynamic model of the high-speed bearing with the pits considering the intermittent working conditions is proposed to analyze the effects of the types of the pits on the time-varying contact excitations. (3) According to the coupling relationship between the types of the pits and the multiply uniform time-varying impulses, an adaptive signal feature extraction and detection model is presented to improve the accuracy of the detection method of the pits in the high-speed bearings in the large wind turbines. This work can provide some guidance for the new methods of the excitation mechanism, vibration characteristics and signal feature extraction and detection of the high-speed bearings in the large wind turbines.

随机风载、高速轴不对中、扭振等多源激励与间歇工作机制的耦合作用是导致大型风电机组齿轮箱输出端与发电机输入端高速轴承出现点蚀坑带类损伤故障主要原因之一，对其激励机理、振动特征及其信号识别的认知程度决定了高速轴承运行状态判定的精准性与可靠性。以高速轴承为研究对象，对其故障机理、振动特征与识别进行研究。具体内容：（1）研究高速轴不对中与挠曲变形耦合的高速轴承点蚀坑带类损伤故障的激励机理，解决上述故障与高速轴承不对中时变冲击激励、挠曲变形之间的映射关系难题；（2）研究间歇工作机制下高速轴承点蚀坑带类损伤故障的动力学建模，解明该类故障与其时变接触激励之间的映射关系；（3）研究点蚀坑带类损伤故障诱发的多个非均布缓变冲击激励间的耦合关系，建立其振动信号自适应识别模型，实现其精准识别。本研究旨在为大型风力发电机高速轴承点蚀坑带类损伤故障的激励机理、振动特征及其信号的提取与识别提供新的方法和理论支撑。

随机风载、高速轴不对中、扭振等多源激励与间歇工作机制的耦合作用是导致大型风电机组齿轮箱输出端与发电机输入端高速轴承出现点蚀坑带类损伤故障主要原因之一，对其激励机理、振动特征及其信号识别的认知程度决定了高速轴承运行状态判定的精准性与可靠性。项目以高速轴承为研究对象，对其故障机理、振动特征与识别进行研究。研究了高速轴不对中与挠曲变形耦合的高速轴承点蚀坑带类损伤故障的激励机理，解决上述故障与高速轴承不对中时变冲击激励、挠曲变形之间的映射关系难题；研究了间歇工作机制下高速轴承点蚀坑带类损伤故障的动力学建模，解明该类故障与其时变接触激励之间的映射关系；研究了点蚀坑带类损伤故障诱发的多个非均布缓变冲击激励间的耦合关系，建立了其振动信号自适应识别模型，实现其精准识别。本研究为大型风力发电机高速轴承点蚀坑带类损伤故障的激励机理、振动特征及其信号的提取与识别提供新的方法和理论支撑。