Research On The Topology And Control System Of A Novel Hybrid Stator Bearingless Switched Reluctance Motor

The Bearingless Switched Reluctance Motor(BSRM)integrates a Switched Reluctance Motor(SRM)and a magnetic bearing,which can simultaneously achieve the rotation and suspension of the motor.BSRM has the advantages of small size,light weight,and good high-speed performance,and has significant application characteristics in high-speed fields such as aerospace and flywheel energy storage.Traditional bearingless switched reluctance motors always have the following problems: severe coupling between torque and suspension force,making it difficult to achieve complete decoupling and coordinated control of torque and suspension force;Due to limitations in its own structure and operating mechanism,it can only operate as a two-phase system,resulting in a torque dead zone;The complex topology structure leads to low practicality of the motor.In response to the above issues,this article proposes a new 18/16 pole hybrid stator type bearingless switched reluctance motor.The motor has a simple structure,with two types of teeth in the stator,which respectively control the rotation and suspension of the motor.The structure realizes the natural decoupling of torque and suspension force,while the electrical torque adopts a three-phase operation design,eliminating the problem of torque dead zones in two-phase operation.Firstly,the design requirements and structural characteristics of the new motor were presented,and an appropriate excitation method was analyzed and selected to determine the structure of the new motor.The torque and suspension characteristics of the new motor were analyzed through finite element simulation.Derive a new motor torque mathematical model and conduct simulation verification;Based on the spatial distribution characteristics of the new type of motor suspension teeth,the control mechanism of suspension force under different winding forms of the suspension winding is analyzed,and a mathematical model of suspension force under the star winding form is derived and verified through simulation.At the same time,the focus is on researching the control strategy of a new type of motor suspension system,with the goal of improving the suspension force control performance and reducing the hardware cost of the control system.The suspension winding is considered to adopt a star connection method,and a three-phase full bridge inverter is used as the main driving circuit of the suspension force control system,Propose a suspension force control strategy based on three-phase full bridge inverter and space vector pulse width modulation(SVPWM),and conduct simulation verification.On this basis,a new levitation force control strategy was proposed by integrating the advantages of single cycle algorithm and space vector pulse width modulation technology.The state switching criteria of the new single cycle control strategy were optimized,and mathematical models of the seven segment and five segment single cycle algorithms were established.Simulation verified that the new single cycle algorithm has a lower current ripple content and higher levitation force control accuracy,The proposed single cycle suspension force control method can be applied to three pole or six pole magnetic bearings driven by three-phase inverters,with good universality.Finally,the overall control diagram of the new motor was provided,and a new motor model was built in Matlab/Simulink.The dynamic characteristics of the new motor were simulated and analyzed,and the good decoupling control effect of the new single cycle algorithm on the radial two degrees of freedom suspension force control of the new motor was verified.The output torque of the new motor met the design requirements.