Design Of Switched Reluctance Motor For Electric Motorcycle

Switched reluctance motor(SR motor) has many advantages such as simple structure,low cost,wide speed range and reliable operation,which can be widely used in transportation,aviation,industrial manufacturing and other fields.The characteristics of SR motor are quite consistent with the performance requirements of electric vehicle for driving motor,and energetically developing electric vehicle can effectively reduce carbon emissions,save energy,and help to achieve the national strategic goal of "Carbon Peaking,Carbon Neutrality".In this paper,the research on switched reluctance motors for electric motorcycle is carried out,and the main works are as follows:1)A switched reluctance motor with rated power of 4kW and rated speed of 9000 rpm was designed.Combined with the requirements of the drive motor for electric motorcycle,the structural dimensions of the stator and rotor of the motor were designed based on the basic principles of the SR motor,and the winding and electromagnetic parameters of the SR motor were designed based on the magnet circuit method,then the basic structural dimensional parameters and electromagnetic parameters of the motor were obtained.The validity of the designed motor is verified by finite element simulation.On this basis,3d modeling software is used to design the motor housing,rotating shaft,end cover and other parts,and the 3D overall assembly drawing of the SR motor is given.Finally,a prototype was developed to validate the effectiveness of the design scheme.2)An analytical method is proposed to analyse the strength of the rotor of high-speed SR motor.In the process of high-speed operation,the structural strength of the rotor may not be able to withstand the huge centrifugal force.Therefore,it is necessary to analyze the stress in the rotor during high-speed operation to ensure that the rotor stress is less than the ultimate strength of the material.Firstly,the stress distribution of axial section of salient pole rotor of SR motor is analyzed.Then,based a planar stress model,the stress function method is used to derive the expressions of the stress and radial displacement of the convex pole rotor in the SR motor.Finally,the rotor stress of SR motor proposed in this paper are analyzed by analytical method and finite element method,and the validity of analytical method is verified.3)A new stator structure is proposed to suppress the torque ripple of SR motor.A wedge is added to both sides of the stator magnet extremities to reduce the sudden change in the air gap at the start of stator-rotor overlap,which reduces the sudden change in air gap magnetic field energy and thus reduces torque ripple.The influence of the parameters of this special wedge structure on the electromagnetic performance of the SR motor was first analysed.Based on this,the three-dimensional visualization algorithm was used to optimize the parameters of the wedge structure with multi-objective constraints,and the optimal parameter set was obtained.Finally,the finite element method was used to simulate the effectiveness of the design scheme.The results show that the wedge-shaped structure can restrain the torque ripple effectively and has little influence on the average torque of the motor.