风力机传动系统行星齿轮初期故障的精细诊断研究

There exist three problems in earlier localized fault diagnosis of planet gear in the planetary gearbox of a wind turbine, which are (1) traditional denoising algorithm cannot deal with the interruption generated by the parallel gearbox, (2) the weakness of the earlier fault will aggravate the phenomenon of “Same appearance different causes”, and this will make the diagnosis result with traditional strategy doubtable, (3) traditional algorithms for the planet gear cannot distinguish different types of earlier faults which will affect the formulation of later maintenance strategy. To address these problems, the meshing resonance phenomenon is taken as the key breakthrough point, and the precise earlier fault diagnosis of planet gears is realized by using the dynamic modelling and experimental analysis together in this project. In detail, a meshing resonance phenomenon based algorithm is primarily proposed to directly highlight the planet gear related vibration to realize the elimination of parallel gearbox interruption, the differences on time domain aggregation and modulation mechanical of meshing resonance between gear error and local gear fault are then fully employed to implement the separation of these two components, and the detection of earlier planet gear fault is carried out together using the revised time synchronous average method and meshing resonance demodulation, The precise fault diagnosis of the planet gear fault diagnosis is finally accomplished based on the study of the way different types of earlier fault can influence the system kinetic characteristics based on dynamic modelling and corresponding vibration feature though experimental tests. Research results are of great significance for ensuring the operational stability of wind turbines.

风力机行星轮系行星齿轮的初期局部故障诊断存在问题：（1）现有的消噪算法难以去除平行级振源的干扰；（2）初期故障的微弱性将放大同相异因现象，使传统的诊断策略难以得到可信的结果；（3）现有的诊断方法难以区分不同种类的初期局部故障，不利于后期故障诊断策略的制定。针对上述问题，本项目拟以啮合共振现象为突破口，结合动力学建模与实验分析实现行星齿轮早期故障的精细诊断。具体的，提出了利用啮合共振现象直接定位并突出行星齿轮相关振动的思路以实现平行级干扰的消除；提出利用齿轮误差与局部故障在时域聚集性和啮合共振调制机理上的差异实现二者分离的策略，联合应用改进的时域同步平均算法与啮合共振解调实现行星齿轮初期故障的识别；采用动力学建模手段研究不同类型初期故障对系统宏观动力学特性的影响规律，并结合实验研究获取相应的振动特征，实现行星齿轮初期局部故障的精细诊断。研究成果对保障风电装备运行稳定性具有重要意义。

风能是我国乃至世界范围内发展速度最快的可再生能源之一。风力发电是我国能源安全的重要保证，对发展低碳产业、节能减排具有重要意义。但是，目前我国在役风电装备饱受运行效率低、故障率高、可靠性差等问题的困扰，其中风电行星轮系因其高故障率、高维修成本与长停机时间成为风电装备传统系统故障诊断与状态监测的重点。在实际工程中，风力机行星齿轮箱复杂的结构特点和运行模式使得相应的故障诊断尤其困难。为此，本报告以风力机行星齿轮系为对象展开故障诊断研究。首次考虑定轴轮系的强干扰，发现了“啮合共振”现象，并提出了基于“啮合共振”现象的诊断框架，分别解决了风力机行星齿轮齿根裂纹故障、齿圈局部故障的定位和诊断以及行星齿轮轴承局部故障诊断等问题。另外，还将“啮合共振”的思想推广至定轴轮系，发现了能够表征齿轮故障的新特征，并解决了定轴轮系复合故障诊断的问题。本报告结合典型风力机行星轮系行星轮局部故障案例阐述定轴轮系噪源对风力机行星轮系故障诊断的影响机理。并针对这一问题提出了新的基于“啮合共振”现象的风力机行星轮系故障诊断框架。“啮合共振”现象指的是即使没有局部故障，一对齿轮互相啮合也会引起类似共振的现象：即，啮合频率会被调制到一个特定的频带区间。我们将这个特定的频带称为啮合共振区。本报告构建诊断框架的核心是通过对啮合共振区的定位实现行星轮相关振动的增强。