Active Vibration Control For An Active Magnetic Bearing-Rigid Rotor System

The active magnetic bearings(AMBs)can realize the rotor rotating in such high speed which is difficult to be achieved by the traditional mechanical bearing,due to it can provide the contactless supporting for the rotor and can also active control the rotor features by means of the certain control strategy.At present,the AMBs have become the main support unit in high-speed rotating machinery such as high speed motor and high speed flywheel energy storage.In this paper,the active control of AMBs-rigid rotor system is presented.Firstly,the working principle of AMBs-rigid rotor system and the linear modeling of radial electromagnetic force of AMB are carried out.Then,a single disk rotor(planar rotor)model with 2-degree-of-freedom(DOF)is analyzed,on this basis,the dynamic model of a radial 4 DOF AMB-rigid rotor system with rotor imbalance is given.Finally,the stability control,unbalance vibration control and multi-frequency vibration control of AMBs-rigid rotor system are analyzed.For the stability control of AMB-rigid rotor system,the decentralized PID control and linear state feedback decoupling control are proposed.In order to give the basis for selecting PID controller's parameters,the influences for rotor motion characteristics with PID controller are discussed.And the linear state feedback decoupling control is proposed for yroscopic coupling effect.Finally,the effectiveness of the two stability control strategies is verified by simulation.For the unbalance vibration control of AMBs-rigid rotor system,an unbalance vibration displacement control based on unbalance coefficients identification is proposed to suppress the rotor unbalace vibration displacement.Firstly,the form of compensation currents is analyzed and the unbalance cofficients are defined.Then,the unbalance coefficients identification equation is presented and the stability of the closed-loop system is discussed.The simulation model of AMB based flywheel energy storage is established to verify the displacement control algorithm under constant speed,constant acceleration and noise environment.For the multi-frequency vibration control of AMBs-rigid rotor system,a multi-frequency vibration suppression method is given.A multi-frequency current coefficients identification algorithm based on variable step size triangle iterative search is proposed to implement a multi-frequency currents controller.The simulation model of AMB based high speed rotor is established to verify the multi-frequency currents compensation algorithm under constant speed,constant acceleration and noise environment.In this paper,the AMBs high speed motor and flywheel energy storage system experiment platforms based on dSPACE are introduced.And the validity of the stability control method,unbalance vibration control method and multi-frequency vibration control method proposed in this paper are confirmed.