基于轴向力自由控制的磁悬浮飞轮基座振动抑制
Suppression of base vibrations in a magnetically suspended flywheel system based on axial force free control

高速磁悬浮飞轮壳体或机座振动是影响运行精度的关键问题。对于外转子式飞轮结构，当转子轴向基准面与转子旋转轴线之间的垂直度精度在一定范围内时，这种形位误差会导致额外的基座振动。基座的同频振动幅值由转子自身的残余不平衡和位移传感器测量面的形位误差同时决定。因此，该文在传统力自由控制基础上提出了轴向力自由控制方法对基座的轴向振动进行抑制。通过实验比较了不开启不平衡控制、仅开启径向不平衡控制和同时开启径向、轴向不平衡控制3种情况，验证了在转子各自由度同时开启不平衡控制能更有效地减小基座振动。实验结果表明：在工作转速下，该方法能有效地消除转子轴向的同频振动力，抑制基座振动。同时，也证明了在承担重力方向同样也能实现力自由控制，与磁轴承仅有径向力自由的不平衡控制方法相比，拓宽了不平衡力自由控制方法的应用领域，取得了较好的振动控制效果。
Abstract：Vibrations of the housing or base is one of the key problems influencing the running accuracy of high-speed magnetic suspended flywheels. Flywheel rotors with an outer-rotor structures have geometrical errors that cause base vibrations when the angle between the normal to the axial reference plane and the rotor spinning axis is within a specific range. The amplitude of synchronous vibrations of the base is mainly determined by the rotor unbalance and geometric error in the measurement plane of the displacement sensor. Base vibrations are suppressed here by an axial force free control method based on conventional force free control. Three controllers were analyzed in tests with no unbalanced control, only radial unbalance control and radial-axial unbalance control. The unbalanced control simultaneously acts on differ degrees of freedom of the rotor to more effectively suppress the base vibrations. Tests show that, at full operating speed, the control method effectively eliminates axial synchronous vibrations in the rotor and then suppresses base vibrations. Force free control can also be applied in the direction of gravity. This axial force free control achieves better vibration suppression performance and has wider applications field than conventional force free control of magnetic bearing