Stiffness analysis for bearingless switched reluctance motor with bias permanent magnet

In the high speed industrial application, bearingless motor, which integrates advantages of magnetic bearing into motor, has received more and more attention.[1-2] In this paper, stiffness analysis for one novel bearingless SRM with bias permanent magnet is investigated. Fig.1 shows the basic structure and prototype motor. It´s a radial suspending structure equipped with permanent magnet to provide bias flux. The independent torque pole and suspending pole make the suspending flux and torque flux decoupled, and the independent X and Y channel control make the X and Y channels´ suspending fluxes decoupled. Firstly, the proposed structure and operation principle are introduced in detail. Secondly, the mathematic model is built to calculate the proposed structure´s suspending force and stiffness. What´s more, the finite element analysis and experiment results are used to verify the motor performance.