Research On The Method Of Suppressing Torque Ripple Of 12/8 Pole Single-Winding Bearingless Switched Reluctance Motors With Wider Rotor Teeth

Compared with switched reluctance motor(SRM),bearingless switched reluctance motor(BSRM)eliminates mechanical bearings.It not only inherits the advantages of bearingless motors such as frictionlessness and long life,but also has a simple structure and high reliability.It has important application research value in the field of high-speed motors such as aerospace and automotive.However,the torque and levitation force of ordinary BSRM have a strong coupling,which affects the running performance of the motor and the control will become relatively complicated.In order to solve this problem,the researchers proposed a wide rotor toothed bearingless switched reluctance motor(BSRMWR)with a decoupling structure.This motor realizes the decoupling of torque and levitation force through structural changes.Although BSRMWR realizes the decoupling of torque and levitation force,due to its stator and rotor lenticular structure and pulsed power supply mode,there is a problem of large torque ripple.Excessive torque ripple seriously affects the stability of the motor and greatly reduces the operating efficiency of the motor.Therefore,reducing the torque ripple of the BSRMWR has practical research significance.Firstly,the structure of BSRMWR and ordinary BSRM is compared and analyzed.The principle of double-phase conduction and decoupling of 12/8-pole single-winding BSRMWR is introduced,the mathematical model of torque and levitation force of 12/8-pole single-winding BSRMWR is derived using Maxwell's stress method,and the mathematical model of levitation force is improved.It also introduces its power converter and the torque characteristic model and levitation force characteristic model obtained by finite element simulation to lay the foundation for subsequent motor control.Secondly,the application of traditional current chopper control strategy in BSRMWR is introduced,the problem of excessive torque ripple is pointed out,and the cause is analyzed.According to the unique mathematical model of BSRMWR,in order to suppress the torque ripple of the BSRMWR motor,a control strategy based on the motor's turn-on and turn-off angles to optimize the winding current is proposed.Through the combination of theoretical analysis and experimental simulation,the torque and levitation force under the angle optimized control strategy and the traditional current control strategy are compared.Then,Abandoning the traditional current control and starting directly from the control goals: torque and levitation force.Based on 12/8 pole single winding BSRMWR,the two-phase direct torque control(DTC)and direct levitation force control(DFC)are proposed.The basic principle of the twophase DTC & DFC control strategy is introduced,and the simulation model is set up.The simulation results are compared with the simulation results of the angle-optimized control method based on the current control strategy.Finally,the design of the BSRMWR hardware experimental control platform is introduced,and the design of the motor control program based on DSP2812 is introduced.Based on the above control system,current chopping experiments,static levitation experiments,and two-phase conduction decoupling experiments were performed.The experimental results are analyzed in detail.