Design And Control Of A Bearingless Flux-Switching Motor

Without the permanent magnet on its rotor,bearingless flux-switching permanent motor(BFSPM)is especially suitable for disposable and high temperature applications such as biochemical process and medical chemistry.In this paper,technologies about BFSPM are investigated.According to the principle of flux-switching and Maxwell force,the torque and levitation force generation are explained.Then the relationship between levitation force and rotor angle is deeply researched.By establishing the mathematical model of levitation force,two control strategies are deduced.The advantages and disadvantages of the two control strategies are compared in detail.In order to solve the problem of serious levitation force distortion and reduce control difficulty,the influence of the rotor parameters on levitation force distortion is discussed.For further improvement of force performance,a new structure is studied in this paper.Theoretical analysis shows that most even harmonics and DC component are eliminated so that the levitation force is optimized and control strategy is simplified.Then a prototype of BFSPM is designed.The geometric parameters are designed in detail.By 3D finite element simulation,torque and force performance are verified.Finally,the prototype is successfully manufactured and parameters are measured.The control platform of bearingless flux-switching motor,which is based on DSP28335,is built and the software system is also designed in this paper.Stable levitation operation is realized successfully.The experiments fully verified the feasibility of BFSPM.