Design And Analysis Of Field Modulated Two-Degrees-of-Freedom Flux-Switching Machine

The field-modulated two-degrees-of-freedom flux-switching(FM-2DoFFS)machine,capable of rotary,linear,and helical motions,is a novel two-degrees-of-freedom machine based on the flux-switching(FS)principle.Due to the advantages of compact structure,high integration,high utilization of permanent magnet(PM),weak magnetic–coupling,etc.,the FM-2DoFFS machine has wide application prospects in the field of robots,top-end machine tools,semiconductor packaging,and so on.This thesis studies the FM-2DoFFS machine based on air-gap magnetic field modulation theory(AMFMT).The three-dimensional(3D)modulation model of the FM-2DoFFS machine,which is evolved from the two-dimensional(2D)modulation model of the single-degree-of-freedom flux-switching(SDoFFS)machine,is built to reveal its electromagnetic characteristics,including induced electromotive force(EMF),torque/thrust,and winding inductance in different motion forms.Furthermore,a harmonic modulating-based torque ripple/thrust ripple suppression method is proposed.In addition,a prototype of the FM-2DoFFS machine is produced and tested to verify the analysis and 3D finite element model(FEM)results.The research lays a theoretical and technical foundation for further in-depth research and development of the FM-2DoFFS machine.The research contents and innovations of this thesis are as follows:1.A novel FM-2DoFFS machine is proposed.To overcome the shortcoming of the existing 2Do F machines,a novel FM-2DoFFS machine composed of a salient-pole mover,a rotary arc-stator,and a linear arc-stator is proposed.Then,its operation principles of rotary,linear and helical motions are explained based on the FS principle.Finally,a 3D FEM of the FM-2DoFFS machine is established to analyze the 3D magnetic field distribution,winding flux-linkage,induced EMF,magnetic coupling induced-EMF,and torque/thrust in different motion forms.2.The 3D air-gap magnetic field modulation theory and method of the FM-2DoFFS machine are proposed to reveal the generation mechanism of rotary/linear induced EMF.The mathematical expression of the 2D initial magnetomotive force(MMF)and stator/rotor modulation functions are derived firstly based on AMFMT.The induced EMF function of the SDoFFS machine,which is obtained from the 2D PM magnetic field and winding function,is established to explain the generation mechanism and necessary conditions.Then,the 3D initial MMF and stator/mover modulation functions of the FM-2DoFFS machine are developed to build the 3D PM magnetic field model.Combined with the 3D winding functions,the generation conditions,mechanism,and characteristics of the induced EMF in rotary,linear,and helical motion forms are expounded.Finally,the induced EMF characteristics are analyzed and verified by 3D FEM.3.The torque/thrust generation mechanism of the FM-2DoFFS machine under 3D magnetic field modulation is expounded.Firstly,based on AMFMT,the armature reaction magnetic field of the traditional FS machine is established to explain the necessary conditions and generation mechanism of the torque by combining it with the PM magnetic field.Then,the 3D armature reaction magnetic field model of the FM-2DoFFS machine is built.According to the relationship between the 3D armature reaction and PM magnetic fields,the necessary conditions and mechanisms for the static,rotary,linear,and helical harmonics to generate torque/thrust in different motion forms are obtained.Finally,the torque/thrust characteristics of the FM-2DoFFS machine are analyzed and verified by 3D FEM.4.The rotary/linear winding inductance model based on 3D magnetic field modulation is derived to expound the winding inductance mechanism of the FM-2DoFFS machine.Firstly,based on the single-phase winding magnetic field and winding function of the SDoFFS machine,the contribution of the single-phase winding magnetic field harmonics to the winding inductance is explored.The reason for the winding inductance characteristics and the similar d-and q-axis inductance are explained.Then,3D modulation models of the rotary and linear part single-phase winding magnetic fields are established to derive the winding inductance function of the FM-2DoFFS machine by combining the 3D winding functions.The winding inductance principle and characteristics are analyzed by the rotary,linear,and helical harmonics of the single-phase winding magnetic fields.Finally,the winding inductance is calculated and verified by 3D FEM.5.A fast design method and a harmonic modulating-based torque/thrust ripple suppression method are put forward.Firstly,the FM-2DoFFS machine is fast designed according to the similarity between the rotary and linear parts.Then,according to the mapping relationship between the harmonics and torque ripple,a harmonic modulating-based torque ripple suppression method is proposed to suppress the torque/thrust ripple of the FM-2DoFFS machine.Then,compared with the previous torque ripple suppression methods,the proposed method exhibits the best comprehensive performance confirming its advanced nature.Finally,the double-direction cos mover applied to the FM-2DoFFS machine is proposed to suppress the torque ripple/thrust ripple.In addition,the mover can improve the magnetic field harmonics,cogging torque/force,and induced EMF according to the 3D FEM results.6.A prototype of the FM-2DoFFS machine is manufactured to conduct the experiments.A prototype of the FM-2DoFFS machine is manufactured.Meanwhile,its comperhensive experimental system and test platform of the prototype is designed and built.The characteristics of the prototype are tested to verify the 3D FEM and analysis results.