Design,analysis And Optimization Of A Double-rotor Hybrid Excited Axial Switched-flux Permanent Magnet Machine

Electric vehicle will be the future direction of the automobile due to the advantages of energy conservation and environmental protection as well as high intelligence.Because of the merits of simple and compact structure,short axial length,high power/torque density,low-speed large torque and wide constant power operating range,the hybrid excited axial switched-flux permanent magnet machine has a good application prospect in some wide speed-regulation areas such as electric vehicle.Based on a novel double-rotor hybrid excited axial switched-flux permanent magnet(DRHE-ASFPM)machine,a comprehensive study on optimum topology,design method,structure optimization,electromagnetic performance,cogging torque,experimental verification and performance evaluation is implemented in this thesis.It will provide theoretical and technical foundation for the further research and application.Firstly,a novel DRHE-ASFPM machine is proposed.The operating principle is analyzed and the flux-regulation mechanism is revealed.The power size equation of the DRHE-ASFPM machine is established and the electromagnetic design principle is explored.The general design method is summarized and the initial design is completed.Secondly,the electromagnetic performance of the machine based on initial structural parameters is analyzed.The influence of the stator and rotor parameters on the electromagnetic performance of the DRHE-ASFPM machine is investigated,and the optimal design of the DRHE-ASFPM machine is implemented.The electromagnetic performance of 4 machines,including the 6-slot/10-pole,6-slot/11-pole,6-slot/13-pole,and 6-slot/14-pole combinations,is comparatively analyzed and the optimum slot/pole combination machine is confirmed.Then,the electromagnetic performance of the DRHE-ASFPM machine is studied deeply,and compared with the initial design.The characteristics of the DRHE-ASFPM machine and the validity of the optimization method are verified.In order to reduce the cogging torque of the DRHE-ASFPM machine,the analytical equation of the cogging torque is established.Three cogging torque reduction methods,including stator/rotor teeth notching,stator slot chamfering,and stator slot chamfering and teeth notching,are proposed.The cogging torque,back-EMF,electromagnetic torque and flux-regulation capability of the DRHE-ASFPM machine based on the proposed methods are comparatively investigated.As a result,the operating performance of the machine is further improved.Finally,according to the optimized structural parameters,the experimental prototype is manufactured,and the test platform based on MicroLabBox is built.The experimental research is carried out to assess the performance of the DRHE-ASFPM machine,and verify the characteristics of the machine and the correctness of theoretical analysis.