A Novel Controller with Force Feedback of Active Magnetic Bearings

A novel force feedback controller is presented to overcome disturbing forces acting on magnetic suspended rotors of Active or Hybrid Magnetic Bearings (AMB or HMB). As there is linear relationship between disturbing forces and changes of magnetic field on bearings’ operating point, the force feedback is implemented by measuring bearings’ magnetic flux density by hall components. Detailed analysis is discussed also, the dynamic stiffness and damping of the controlled plant are increased when force feedback added into the controller; meanwhile, dynamic response of power amplifier is improved as the novel controller provides a zero point that counteract with the pole point of the power amplifier. A novel controller is developed based on conventional PID leading correcting network. Both simulation and experiment indicate that this novel controller can effectively decrease the influence of disturbing forces, and thus improves the controller’s performance.