Vibration characteristics analysis of magnetically suspended rotor in flywheel energy storage system

The detailed relationship between the vibration characteristics of the magnetically suspended rotor (MSR) and system parameters is modeled and analyzed experimentally in this article. The results indicate that the stiffness of the MSR is tunable by regulating the proportional coefficient of the control system such that the desirable natural frequency of the MSR can be achieved. Damping of the MSR is also controllable by regulating the derivative coefficient of the control system. Therefore, the natural frequency of the rotor can be tuned far away from the working frequency in order to avoid the resonant vibration, and the transmissibility amplitude can be mitigated by tuning the damping. Furthermore, the tilting responses of the MSR with different disturbances are analyzed. The results show that the tilting angle of the MSR decreases with the rotational frequency when the impulse disturbance is imposed on the MSR, but the titling angle increases with the rotational frequency when the harmonic disturbance is acting on the MSR. As a result, the vibration analysis and control of the MSR can be realized based on the tilting angle response. Both simulation and experiment are conducted to verify that the torque generated by the radial active magnetic bearing can suppress the vibration of the MSR.