Design And Control Of A Novel 12/14 Hybrid Stator Pole Type Bearingless Switched Reluctance Motor

Bearingless switched reluctance motor (BLSRM) is developed on the basis ofmagnetic bearing motor and switched reluctance motor (SRM). BLSRM not only extendstheory and application of the bearingless motor, but also inherits high-speed performanceand adaptability to atrocious surroundings of the SRM. Hence, BLSRM has broad prospectof application in high-speed, aerospace and other fields.Based on the torque control coupled with the suspending force control in traditionalBLSRM and low output power density in the 8/10 hybrid stator pole type BLSRM, thispaper proposes a novel 12/14 hybrid stator pole type BLSRM. The proposed structure hasseparated torque and suspending force poles, so the torque control can be decoupled fromthe suspending force control. Moreover, due to the short flux path without any reversal fluxin the stator core, compared to the 8/10 hybrid stator pole type BLSRM, the output torqueis significantly improved. To verify the proposed structure, the proposed structure isdesigned according to 8/10 structure, and finite element method (FEM) is employed to getthe characteristics of the proposed and 8/10 structures with the rotor in the center position,including magnetic flux distribution, inductance, torque and suspending force. Meanwhile,the effect of rotor eccentricity on the motor performance in the proposed structure is alsoanalyzed.In order to verify the correctness of the finite element analysis results, a prototype ofthe proposed BLSRM is designed and manufactured, and the inductance of the prototypeBLSRM is measured. Compared the inductance measured from the prototype to thatobtained from FEM, it can be seen that the measured and finite element analysis resultshave a good match, which verifies the correctness of the finite element analysis results.In order to verify the validity of the proposed BLSRM, a control scheme for theproposed BLSRM is proposed based on torque control and suspending force controlnatural decoupling characteristics in the proposed structure. According to the proposedcontrol scheme, simulation model and experimental system are constructed, and the dynamic characteristics simulation and experiment are performed to the proposed BLSRM.From the simulation and experiment results, it can be seen that the motor can steadilyoperate, the motor speed can be up to 2000r/min and the rotor eccentric displacement errorcan be controlled within±30μm in real-time control, and the torque control can bedecoupled from suspending force control in the proposed structure, which verifies thevalidity of the proposed BLSRM and its control scheme.