Research On Full-peorid Mathematical Model And Novel Control Strategy Of Single-winding Bearingless Switched Reluctance Motor With Hybrid Rotor

Bearingless Switched Reluctance Motor(BSRM)integrates Switched Reluctance Motor and magnetic bearing,it can realize rotation and suspension at the same time.Because BSRM has the advantages of small size,light weight,good high-speed performance,etc,it has significant application characteristics in high-speed fields such as aerospace and flywheel energy storage.The traditional 12/8-pole BSRM has a strong coupling between the torque and the suspension force,which seriously affects the output performance of the motor.BSRM exists a suspended dead zone due to the structural limitations.When the stator and rotor run to a completely misaligned position or the overlapping area between stator and rotor is very small,the electromagnetic force is just a little,the rotor cannot be suspended normally.Based on the traditional BSRM,Single-winding Bearingless Switched Reluctance Motor with Hybrid Rotor(HSBSRM)introduces a cylindrical rotor.The magnetic resistance between the cylindrical rotor and the stator is small,so the cylindrical rotor not only can generate a large suspension force,but also can compensate the suspension dead zone of the traditional BSRM.This is the reason why HSBSRM is able to achieve full-position suspension.Combined with the characteristics of full-position suspension,the torque output interval of HSBSRM is controlled in the inductance rising area,and the suspension force output interval is controlled in the inductance flat top area,so that the decoupling control of torque and suspension force can be realized.Because of the full-position suspension and self-decoupling structural characteristics,the control strategy of HSBSRM will be more flexible.Firstly,the structure and working principle of HSBSRM are introduced.Under the condition of ignoring magnetic flux leakage and edge flux,a more accurate mathematical model of HSBSRM is derived with the re-divided magnetic circuit.The superiority of the novel mathematical model of HSBSRM is verified by the simulation comparison with the traditional mathematical model.The superiority of the full-peorid mathematical model is verified by the simulation comparison with the traditional mathematical model.Then,the decoupling control strategy of HSBSRM is introduced and the simulation model is built in Simulink based on the full-cycle mathematical model to verify the feasibility of the decoupling control strategy.However,when HSBSRM adopts decoupling control,the output torque ripple is large and the output performance is poor.In order to solve the above problems,a torque compensation control strategy suitable for HSBSRM and BSRM is proposed,and a detailed simulation analysis of it is carried out,which confirms the correctness of the torque compensation control strategy.Considering the cost of the motor control system,combined with the structural characteristics of full-position suspension,a full-cycle suspension control strategy and a new type of half-bridge power circuit are proposed in this paper.The control principle and control algorithm of the full-cycle suspension control strategy are described in detail,the working principle of the new half-bridge power circuit is also explained.To verify the correctness of the full-cycle suspension control strategy,the HSBSRM model was built in Simulink with the novel mathematical model.This paper simulates and analyzes the output characteristics of HSBSRM in various operating states,and the full-cycle suspension control strategy was optimized according to the simulation analysis results,which further improves the accuracy of the full-cycle suspension control strategy.