风电叶片疲劳加载过程频率俘获特性

Frequency Capture Characteristics in Wind Blade Fatigue Loading Process

为了研究风电叶片振动过程的频率俘获特性,建立一套摆锤驱动的风电叶片疲劳加载系统,根据拉格朗日力学原理推导出两者的动力学模型,并给出了机电耦合数学模型。编制仿真模型,充分解释了两者的频率俘获过程,定性揭示了该系统的自同步振动特性。多次疲劳加载试验结果表明:当摆锤回转驱动频率在0.48～0.58 Hz时,不仅摆锤回转系统会发生回转频率俘获,风电叶片同样会产生振动频率俘获;随着回转驱动频率的增大,叶片的俘获频率也相应增大。当驱动频率<0.43 Hz或>0.65 Hz时,叶片振动频率不会被俘获,表现为振动频率的上下波动,回转驱动频率越远离俘获区间,叶片频率及振幅的波动越明显。

In order to study the frequency capture characteristic of wind turbine blade,a wind blade fatigue loading system with an unbalanced rotating shaft was established.With the Lagrange principle,the kinetic model was deduced and the coupling mathematical model was given.The simulation models fully explained the frequency capture process,and revealed the vibration self-synchronous properties.A series of wind blade fatigue loading trials proved that when the drive frequency was 0.48~0.58 Hz,frequency capture phenomenon would carry out,not only the pendulum would happen,but also the wind turbine blade.When the drive frequency was out of 0.43 ~ 0.65 Hz,frequency capture phenomenon would not carry out and it would fluctuate obviously,and the more far away of the frequency capture points,the more obviously the wind turbine blade frequency and amplitude fluctuated.