Research On A Novel Type Of Hybrid Excitation Switched Reluctance Motor With Segmental Rotors For Electric Vehicle Applications

With the increase of the car ownership,the development of the traditional automobile industry has brought two major problems: energy shortage and environmental pollution,and the electric vehicles(EVs)have become research hotspots.As a key component in EVs,the output characteristics of driving motor directly affects the performance of electric vehicle.The switched reluctance motor(SRM)has the advantages of simple structure,high fault tolerance,wide speed range and large starting torque.It is very suitable as a driving motor for EVs.A novel 12/8 pole hybrid excitation switched reluctance motor with segmental rotors(HESSRM)is present in his paper,which has 12 permanent magnets located at the stator slot opening of switched reluctance motor with segmental rotors(SSRM).Firstly,the research background and significance of the subject is described in this paper,The development status of the switched reluctance motor and its application in EVs is introduced.The topology structure and working principle of HESSRM is analyzed.The mathematical model of the motor is established,and the equivalent magnetic circuit method is used to verify the principle of magnetization.Secondly,according to the performance requirements of the driving motor for EVs,the design objectives and principles of the motor are proposed.Based on the constraints of the stator and rotor,the pole arc range is obtained.The quasi linear model of the HESSRM is established.Complete the design of the main parameters of the motor,such as the inner diameter,shaft length of the stator,the tooth shape of the stator and rotor,the number of turns of the winding,etc.The Maxwell parametric model is established and the main size parameters are optimized.The flux characteristics and torque performance of the motor before and after optimization are compared.Thirdly,the Maxwell 2D static field model is established,and the characteristics of inductance,flux,torque angle and cogging torque are simulated.The joint simulation model of Simplorer and Maxwell is established to analyze the starting performance and speed regulation performance of the motor.The fault tolerance of motor is analyzed,including open circuit fault,short circuit fault and the ratio of mutual inductance and inductance.Finally,the HESSRM is compared with the SSRM at the same size.The simulation results show that the average torque of HESSRM is 6% higher than that of SSRM.The HESSRM has the lower saturation degree,the larger operation range,and the larger motor utilization coefficient under the high current excitation,which verifies the advantages of HESSRM.