Design And Analysis Of Flux Modulation Hybrid Excitation Machine With Improved Collaborative Modulation Effect

Hybrid excitation machine system aims to combine the advantages of high torque density of PM machine and strong flux adjustment ability of electric excitation machine,which is one of the development directions of advanced machine systems in electric vehicles,wind power generation,aerospace and other fields.Therefore,from the perspective of dual flux modulation produce by hybrid excitation of hybrid excitation machine,this dissertation studies the flux modulation hybrid excitation(FMHE)machine.By making full use of the synergistic effect of dual flux modulation,the torque density and flux adjustment ability are improved.The research content of this dissertation involves the cooperative modulation mechanism,the method of improved collaborative modulation effect,the topology structure design,the optimal control of current ratio and experimental verification,etc.The main research results of this dissertation include the following points:1.The modulation effect of modulation tooth is analyzed,the airgap permeance model of stator tooth with different number of minimum unit is constructed,the influence mechanism of modulation tooth distribution on airgap magnetic field harmonics is revealed,the mapping relationship between modulation tooth distribution and airgap magnetic field harmonics is established,and the effect mechanism of modulation tooth structure change on flux modulation effect is analyzed,which lays a foundation for the flux modulation analysis of hybrid excitation of FMHE machine.2.The analysis model of flux modulation under PM excitation,field winding excitation and armature winding excitation is constructed,the harmonic composition of airgap magnetic field under hybrid excitation is analyzed,the harmonic matching law and action mechanism of airgap magnetic field are proved,the contribution of each working harmonic to torque is calculated by Maxwell tensor method and the collaborative modulation mechanism of hybrid excitation is revealed.It provides a theoretical basis for the collaborative modulation design of FMHE machine.3.Based on the working mechanism of collaborative modulation of hybrid excitation,the separated winding FMHE machine is proposed,the working principle and electromagnetic characteristics of the machine are analyzed and the parallel flux circuit characteristics and the bidirectional flux adjustment ability are revealed.The contribution of the airgap magnetic field working harmonics to the flux linkage is calculated and the electromagnetic performance of the separated winding FMHE machine is evaluated by simulation and experiment.4.In order to reduce the space competition of windings,the field winding and armature winding are integrated into a set of windings,and the topology and design method of the integrated winding FMHE machine are proposed.The mechanism of any number of modulation teeth on the collaborative modulation effect is revealed and the optimal pole slot combination under different number of modulation teeth is derived.The influence of key structural parameters on electromagnetic performance is clarified,which provides a reference for the optimal design of this type of machine.5.The mathematical model of integrated winding FMHE machine is established and a control strategy of maximum torque per ampere based on actual signal injection is proposed,which realizes the accurate tracking and control of optimal ratio of AC current and biased DC current in the actual operation of the machine.The experimental test platform and control system are built and the corresponding experimental research is carried out to verify the effectiveness of the machine design and control strategy.