Compensation control of rotor mass eccentric vibration for bearingless induction motors

Aiming at the rotor mass eccentric vibration caused by the mechanical unbalance of a bearingless induction motor (BL-IM), an unbalance mass radius product (UMRP) strategy is proposed to compensate for rotor displacement. By analyzing the principle and influence of the unbalanced vibration of BL-IM's, a rotating coordinate system is established according to the rotor centroid, the size and orientation of the UMRP is sought by the search algorithm. Then the control signal for the unbalanced vibration compensation is calculated by the compensator, the centrifugal force caused by the mass unbalance is offset by the control signal, and the vibration amplitude of the rotor is weakened. Finally, the compensation effect is verified by the proposed strategy in the MATLAB/Simulink platform and an experimental prototype. Simulation and experimental results show that the rotor displacement peak-to-peak value about 10 mu m. In addition, the radial displacement of the rotor is significantly reduced by the proposed compensation control strategy, and the anti-disturbance capability of the system is improved. The correctness and effectiveness of the proposed method are verified.