Basic Research On The Structure Of Bearingless Switched Reluctance Motor For Vibration Reduction

Bearingless switched reluctance motor is a novel speed-regulating machine.It’s gaining much attention not only for its simple structure,low cost and reliable performance,but also for the adaptability to high-temperature and high-radiation environments.However,the instant change of radial force during phase commutation can result in serious vibration and acoustic noise.To effectively diminish the vibration and acoustic noise,this paper analyzes and compares the characteristics of three new-type BSRMs.This paper is organized as follows:First,the machine structures and suspension principles of different BSRMs are introduced.Then the finite element analysis(FEA)is utilized to better illustrate the magnetic characteristics.To support the machine’s control,this paper also derives the mathematical model of BSRMs based on the virtual work method,considering the eccentric displacements in radial directions.Second,the mathematical model of vibration mode,combined with FEA,is used to carry out the mode analysis.Consequently,the inherent frequency corresponding to each vibration mode is solved.The mode analysis is a decoupled method,which can separate some specific vibration modes and analyzes them independently.The final results can provide theories for the vibration simulation.In bearingless switched reluctance motors with wider rotor teeth(BSRMWRW),the leviation force control can be decoupled from the torque because there is a flat region in the inductance curve of winding,during which the currents can provide levitation force without torque.The decoupling characteristic of levitation force and torque can simplify the machine’s control.This paper sets up the simulation models for the traditional 12/8 BSRM and BSRMWR respectively and studies the vibration responses to radial attractive forces in the square-current control method.Finally,this paper compares the machines structures,working principles and levitation force features of traditional 12/8 and hybrid-stator-teeth BSRM.The vibration responses of stator teeth to the radial attractive force is solved based on the simulation model combined with control strategies in the Matlab/Simulink block.