风力发电机传动系统故障诊断的机电仿真研究

Research of electromechanical simulation model of wind turbine drive train fault diagnosis

为了研究风力发电机组传动系统齿轮故障在发电机电流信号中的响应过程,扩展电流信号诊断方法的应用范围。在考虑齿轮啮合刚度变化和模拟断齿故障变化特征的基础上,建立齿轮副动力学模型;以典型的双馈风力发电机为对象,建立双馈发电机及其控制系统模型。利用齿轮副和发电机的转速参数关联两个模型,构建机电联合仿真模型。在理论上研究齿轮正常或存在断齿时的电流故障特征,并与试验台模拟故障试验比较。仿真与试验结果表明,发电机定子电流可以准确反映齿轮的故障特征信息,且在离网状态下,主要会引起电流信号的频率调制特征。

In order to study the response process of the wind turbine drive train gear fault in the generator current signal, the application range of the current signal diagnostic methods was extended. On the basis of considering the gear mesh stiffness change and simulating the broken gear fault characteristics, the gear dynamics model was built. Taking a typical doubly-fed wind power generator as object, models of doubly- fed generator were set up and its control system using gears and speed parameters of generator was used to link the two models, and electrical and mechanical joint simulation model were constructed. Current fault feature was simulated in the situation of broken teeth gear and normal gear in theory, and the results were compared with the simulation fault test in test-bed. Simulation and experimental results show that the gen- erator stator current accurately reflects the characteristics of the gear fault information, and it mainly cau- ses frequency modulation of current signal in the condition of off-grid.