Performance analysis and design of two magnetic flux oriented control systems for bearingless induction motors

The bearingless induction motor is a strong-coupled complicated nonlinear system. The decoupling control of the torque and radial suspension forces is the base of the stable operation of the motor. In this paper, the principle of radial suspension force is expounded. The mathematics models of the rotation part of the motor and radial suspension force are presented. Then, two control system based on air-gap flux oriented control and rotor flux oriented control are designed. The two control systems are simulated with Matlab/Simulink toolbox. The simulation results have shown that the rotor can suspend steadily, torque and radial suspension subsystems can operate independently. According to the simulation results, the performances of rotor flux oriented control and air-gap flux oriented control are compared and analyzed.