轴承故障会引起双馈异步风力发电机转子气隙变化，产生不平衡磁拉力(UMP)。为准确揭示双馈异步风力发电机轴承故障振动特性，开展了考虑UMP的双馈异步风力发电机轴承外圈故障动力学建模研究。首先，基于赫兹接触理论构建了轴承外圈故障模型；然后，推导了正常和轴承故障下发电机转子的气隙磁密，得到了发电机转子受到的UMP解析式；最后，采用Runge-Kutta法对模型进行求解，得到了轴承故障振动响应。试验分析表明：所提动力学模型能够有效揭示双馈异步风力发电机轴承故障振动信号的双冲击现象，UMP激励会影响风力发电机轴承外圈故障振动信号的调制特性。为风力发电机轴承故障诊断提供了新的理论参考。

Bearing faults can cause changes in the air gap of doubly-fed wind turbines, generating unbalanced magnetic pull (UMP). In order to accurately reveal the bearing fault vibration characteristics of doublyfed wind turbines, a study on dynamic modeling of the outer ring fault of the bearing considering the UMP is carried out. Firstly, a bearing outer ring fault model is constructed based on the Hertz contact theory. Then, the air gap magnetic flux density of the generator rotor under normal and bearing fault conditions is derived, and the UMP acting on the generator rotor is obtained. Finally, the Runge-Kutta method is used to solve the model and the vibration response of the bearing fault is obtained. Experimental comparison analysis shows that the proposed dynamic model can effectively reveal the double impact phenomenon of the vibration signal of doubly-fed wind turbines with bearing faults, and the UMP excitation can affect the modulation characteristics of the vibration signal of wind turbine bearings outer ring faults. A new theoretical references is provided for fault diagnosis of wind turbine bearings.

河北省自然科学基金资助项目(E2021201032)