Structural Design And Analysis Of Axial Flux Dual Rotor Switched Reluctance Motor For Vehicles

Axial flux switched reluctance motor（AFSRM）has the structural characteristics of both switched reluctance motor and disc motor,so it is suitable for electric vehicles and other occasions with narrow axial space.In order to improve the starting torque and power density and realize the axial magnetic tension balance between stator and rotor,in this thesis,the structure principle,design method and output performance of Axial flux double rotor switched reluctance motor（AFDRSRM）for electric vehicle are studied.The main contents of this thesis are as follows:Firstly,aiming at the design method of AFDRSRM,the structure of AFDRSRM and the operation mode of the motor driven by the asymmetric half-bridge converter are discussed.In order to meet the design requirements of AFDRSRM for vehicle drive motor,the concept of "coincidence" of AFDRSRM is introduced.Taking 12/8 pole and 8/6 pole AFDRSRM as examples,the coincidence degree is compared.The AFDRSRM output power and average torque expressions are derived.Based on the above theory,a set of AFDRSRM structure scheme is designed.Secondly,for the torque ripple problem of AFDRSRM,the torque ripple and average torque are analyzed with the stator pole arc coefficient and rotor pole arc coefficient as variables.In order to verify the structure scheme of AFDRSRM,a three-dimensional finite element numerical calculation model is established and solved,and the magnetic flux distribution,flux linkage characteristics,inductance characteristics and moment angle characteristics of the motor of this scheme are analyzed.The field-circuit coupling model is established and solved,and the motor performance of this scheme is analyzed under the conditions of rated load,1.9 times overload and constant power in the angle control mode and the current chopping control mode.Thirdly,for the selection of stator core materials,the application of non-oriented and oriented silicon steel sheets in AFDRSRM is discussed.The average torque and core loss of the motor with two materials under rated and overload conditions are compared and analyzed.In order to reduce the torque ripple,the output torque waveforms of different rotor pole arcs and different rotor pole shapes under single-phase excitation are analyzed.According to the linear torque output characteristics,an improved design scheme of the rotor structure is proposed,and simulation experiments are carried out.Finally,the application of one-way and two-way magneto-thermal coupling methods in the temperature field calculation of AFDRSRM is compared for the temperature rise problem of the double-rotor structure motor.The temperature field distribution of the aforementioned AFDRSRM structure scheme is solved and analyzed.