Research On Single-Winding 12/4 Bearingless Switched Reluctance Motor And Its Control Method

Switched reluctance motor(SRM)is suitable for the worse industrial production environment due to its characteristics of simple and strong structure,strong fault tolerance and good adaptability at high speed.Bearingless switched reluctance motors(BSRMs)which combine the switched reluctance motor with the bearingless motor technology,can significantly reduce the mechanical friction the system volume.Moreover,BSRMs can also more fully meet the high-speed adaptability of SRM through improving the critical speed,and the overall power density can be increased accordingly.The traditional BSRM has the coupling control between torque and suspension force,making it difficult to cope with torque load and radial load.In order to solve this problem,a new type of single winding 12/4 bearingless switched reluctance motor(SRM)is studied in this paper.Firstly,a novel BSRM structure is proposed,which has 12 stator teeth and 4 rotor teeth.The distribution of inductances is analysed to demonstrate the generation of torque and levitation forces,which has natural decoupling characteristics in principle.In order to investigate the relationship between electromagnetic forces and winding currents,the mathematical model of torque and levitation forces is derived,and is verified via Finite Element simulation.Secondly,based on the established mathematical model,the control strategy to regulate torque and levitation forces is proposed in which the torque is controlled by the current chopping control(CCC)method.The demonstrated performance is verified by simulation and experimental results.Finally,in order to investigate the performance by different torque control method,the angle position control(APC)method is adopted to control torque in the proposed 12/4 BSRM.The simulation and experimental results show that the motor has also excellent performance under this strategy.