行星齿轮传动系统机电耦合动态特性与微弱故障诊断研究

Wind turbines have a high failure rate because of the harsh operating conditions and the interaction of various loads. And planetary gear transmissions, as the key transmission device of wind turbines, often endures the coupling action of the dynamic loads caused by the external random wind speed and the reverse impact loads caused by the grid-connected and the low voltage ride-through, which make the system dynamic response complex. Moreover, the complex structure of planetary gear transmissions makes the vibration response signals have the characteristics of response components multiplicity and cross influence, information features weak and strong noise-polluted, which increase the difficulty of fault diagnosis. To solve the problem, this project researches the direct problem and the invers problem of the planetary gear transmissions fault diagnosis in a combined way. Through the research about the direct problem, the electromechanical coupling dynamic model of planetary gear transmissions is established, and the dynamic response mechanism of planetary gear transmissions under the electromechanical coupling action is revealed. Based on the research on the dynamic characteristics and the characteristics of vibration response signals of planetary gear transmissions, because of the unique merit that stochastic resonance uses noise to enhance weak signal features, stochastic resonance method is studied in the project to extract the weak fault features from the complicated signals and thus to diagnose faults of planetary gear transmissions. The main contents of the project include the following: the electromechanical coupling dynamic model of planetary gear transmissions and the mathematical description for different faults, the mapping mechanism of the vibration response to the different faults in the planetary gear transmissions, stochastic resonance enhancement extraction method for weak fault and stochastic resonance inverse method based on resonant response. The research results of this project provide theoretical basis and technical support for planetary gear transmissions weak fault diagnosis, and are of great significance for improving the operational stability and protecting the high reliability and long life of service of wind turbines.

风电装备故障率居高不下，行星齿轮传动系统作为其关键传动装置，长期经受叶轮传递的外部风随机载荷和电压并网、低电压穿越等过程产生的反向冲击载荷等耦合作用，系统动态响应复杂。加之行星齿轮传动系统结构复杂、振动响应成分多样且交叉影响、信息特征微弱、强噪声污染等特点，增加了故障诊断难度。本项目采用正反问题相结合的思想，通过正问题—系统动态特性研究，揭示行星齿轮传动系统的机电耦合动态响应机理；针对反问题—故障特征提取，借助随机共振利用噪声增强信号特征的独特优势，研究微弱故障随机共振诊断方法，实现行星齿轮传动系统微弱故障诊断。研究内容主要包括：行星齿轮传动系统机电耦合动力学建模、行星齿轮传动系统不同故障状态振动响应特性、微弱故障随机共振增强提取方法以及随机共振响应反演方法。本项目研究成果将对行星齿轮传动系统故障诊断提供理论支撑和技术支持，对于提高风电装备运行稳定性、保障其安全可靠运行具有重要意义。

风电机组作为将风能转化为电能的关键设备，故障率居高不下，严重影响风电产业的经济效益和社会效益。而行星齿轮传动系统结构复杂、振动响应成分多样、信息特征微弱、强噪声污染等特点，增加了故障诊断难度。因此，本项目基于正反问题相结合的思想，开展了行星齿轮传动系统动态特征分析与微弱故障增强诊断方法的研究。.首先，开展了行星齿轮传动系统动态特性的研究。建立了行星齿轮传动系统的动力学模型，分析了不同状态下的系统动态响应特性；搭建了双馈异步风力发电机系统模型，实现了前端风速输入到后端发电机电流/电压输出的仿真分析。同时，设计搭建了风电机组传动系统模拟实验台，并建立了斜齿轮双断齿故障的动力学模型，分析了发生双断齿故障时的动态响应，为传动系统复合故障诊断提供理论基础。.其次，开展了微弱故障随机共振增强诊断方法的研究。针对强背景噪声中周期冲击分量难以有效提取的问题，分析了周期冲击信号的随机共振特点，构造了随机共振测度指标，提出了基于自适应随机共振的周期冲击特征增强提取方法；通过分析单一随机共振系统在微弱特征提取中存在的不足，进一步提出了自适应级联随机共振方法，通过对噪声的重复利用，实现周期冲击特征的增强提取。.针对随机共振只能处理小参数信号的局限，将多尺度噪声调节和移频调制相结合，提出了移频多尺度噪声调节随机共振方法；通过分析现有随机共振模型存在的问题与不足，引入时延参数，提出了时延反馈单稳态随机共振方法；并在耦合随机共振的基础上，提出了一种新的耦合增强随机共振方法，提升了算法性能。实验和工程应用实例验证了所提方法的有效性和优越性。.最后，针对滚动轴承故障定量诊断需求，通过分析随机共振响应特点，研究了余弦拟合和频谱校正技术，实现了滚动轴承故障响应幅值信息的定量提取。本项目研究成果可应用于风电机组传动系统运行状态监测与故障诊断，通过开发相应的运行状态监测与故障诊断系统，可为风电机组安全可靠运行提供保障。