Design,Analysis and Control of A Hybrid Axial Field Flux-switching Permanent Magnet Machine

Hybrid axial field flux-switching permanent magnet(HAFFSPM)machine is a novel axial field hybrid excitation machine,and it incorporates the merits of the axial field flux-switching and hybrid excitation machine.It exhibits short axial length,high torque and power density,flexible flux regulation capacity and wide operation range,which make it suitable for direct drive electrical vehicles.In this dissertation,the keys of the theoretical and technical issues about HAFFSPM machine are deeply and systematically studied,including the electromagnetic design,the structure optimization,the static characteristics,the different topologies,the reduction of the back-EMF harmonics and the cogging torque,and the control strategies of the HAFFSPM machine.

Both the simulant and experimental results are given to verify the theoretical analysis.This work lays an important foundation for the further research and application of the HAFFSPM machine in electrical vehicle drive.The research works of this dissertation are as follows:1.The structure characteristics,operation principle and the winding properties of a three-phase HAFFSPM machine are analyzed in detail.The power-size equation of the HAFFSPM machine is deduced,as well as the equation of the relationship among the magneto motive forces generated by the excitation current and permanent magnets and the flux regulation capacity,which lay theoretical base for the design of the HAFFSPM machine.2.Based on the 3-D finite element(FE)method,the static characteristics of the 6/10,6/11,6/13 and 6/14 HAFFSPM machine are investigated,including the field distributions,air-gap flux density,flux linkage at no-load,back EMF,cogging torque,output torque,and flux regulation capacity.

The FE analysis results are compared with that of the theoretical analysis,which verifies the correctness of the design theory of the HAFFSPM machine.3.The influence of the design parameters,such as the spilt ratio,stator tooth width,stator middle tooth width,PM thickness,stator yoke thickness,rotor pole width,rotor pole shape angle,on the electromagnetic performance of the 6/10 HAFFSPM machine is analyzed.In overall consideration of the back-EMF,the cogging torque and the flux regulation capacity,the structure parameters of the 6/10 HAFFSPM machine are optimized based on the design of experiments(DOE)method,and the design scheme of the prototype is obtained.4.The HAFFSPM machines with twisted stators,with segmented twisted rotor,and with asymmetric rotor pole are proposed.