Levitation performance analysis for bearingless switched reluctance motor

The performance of a bearingless motor is determined by the levitation characteristic. This paper shows the levitation performance analysis of a kind of bearingless switched reluctance motor (BLSRM), which separate the levitation control from the torque control. Firstly, the structure and operation principle of the BLSRM are introduced briefly. What´s more, the equivalent magnetic circuit method is employed to build the mathematic models of levitation force and stiffness. In addition, the influences of the structure parameters on the levitation performance are deeply analysed by finite element method. As the motor is an independent structure with separated torque pole and suspending pole, the change of levitation performance results from the torque current is discussed as well. Finally, a prototype motor is designed to test the levitation performance of the proposed motor.