Study On Equivalent Magnetic Circuit Model For A Hybrid Axial Field Flux-Switching Machine

Hybrid excitation axial field flux-switching(HEAFFS)machine is a novel axial field machine,which incorporates the merits of the hybrid excitation machine and flux-switching machine.In this dissertation,the equivalent magnetic circuit(EMC)model of HEAFFS machine is deeply studied,which can provide some reference for the initial design and optimized design of HEAFFS machine.Firstly,the structure and operation principle of a three-phase HEAFFS machine are introduced.Based on the specific dimensions,the static characteristics of HEAFFS machine are analyzed by 3-D finite element method(FEM),including the field distribution,no-load PM flux linkage,back-EMF,cogging torque and flux regulation capability.Secondly,according to the basic theory of the EMC method,the reluctances of each part is deduced and the rotor position is divided.The original EMC model of the whole machine can be obtained by establishing the EMC model of each region.The no-load PM flux linkage and back-EMF calculated by the EMC models are compared with the results calculated by the FEM.Then,the causes of errors are analyzed.Three measures are taken to optimize the original EMC model.The optimization effects are analyzed and the final EMC model is determined.The accuracy of the final EMC model is further validated by the investigation of flux regulation capability.Finally,based on the EMC model,the cogging torque model of the HEAFFS machine is established by energy method.To verify the validity of the cogging torque model,the cogging torque calculated by the model is compared with the result calculated by the FEM.Moreover,the influences of the main structural parameters on the cogging torque are researched.