中文摘要：

克服风电齿轮箱输入转频能量低、输出转频混叠,难以直接提取转速信号的难点,提出了一种基于啮合频率和频谱校正的风电齿轮箱振动信号阶次跟踪方法。该方法利用能量重心法精确估计瞬时啮合频率,间接获得转速信号,进行阶次跟踪,提取风电齿轮箱的运行状态特征。仿真和工程应用结果验证了该方法的有效性和实用性。应用所提方法获得了正常风电齿轮箱振动信号的边频带特性：1）行星轮系的啮合频率同时被太阳轮和行星架的转频调制;2）定轴轮系啮合频率被输出轴的二倍频调制,双弹性支撑导致正常风电齿轮箱输出轴天然地存在轴不对中现象。

英文摘要：

To overcome the difficulty of extracting the rotating speed signal of wind turbine gearbox, which is caused by the low energy of input rotating frequency and the aliasing of output rotating frequency, a novel order tracking method based on meshing frequency and spectrum correction is presented for vibration analysis of wind turbine gearbox. Supported by energy centrobaric correction method, the instantaneous meshing frequency was extracted from vibration signal with high precision firstly, and gained the rotating speed signal indirectly, and then implemented order tracking to extract the running state characteristics of wind turbine gearbox. Simulation and engineering test validated its effectiveness and practicability. Utilizing the novel method, vibration features are successfully obtained from healthy wind turbine gearbox at the site： 1） the meshing frequency of planetary gear train is modulated by the rotating frequencies of sun gear and planet pinion carrier. 2） the meshing frequency of fixed-shaft gear train is modulated by twice the rotating frequency of the output shaft, which reflects a natural output shaft misalignment existed in healthy wind turbine gearboxes.