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
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PU Pengcheng, ZHANG Kai, LIU Pingfan, ZHAO Lei. Suppression of base vibrations in a magnetically suspended flywheel system based on axial force free control. Journal of Tsinghua University(Science and Technology), 2017, 57(9): 993-998.
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