Research On No Yoke And Segmented Axial Flux Permanent Magnet Motor

Axial flux permanent magnet motor has been widely used in recent years and has gradually become the focus of research because of its advantages of compact structure and high power density.There are many kinds of topologies of axial flux permanent magnet motor.With the rapid development of materials,reasonable utilization of core materials for different topologies is one of the key points of research.Axial flux permanent magnet motor has poor heat dissipation performance and high temperature rise.The research on the loss of each part of the motor and reasonable cooling structure is also one of the key points of this kind of motor.Therefore,in order to achieve higher power density and efficiency and promote the wider application of axial flux permanent magnet motor,this paper analyzes the relevant theories and research focuses of axial flux permanent magnet motor,and the main research contents are as follows:（1）Firstly,four topological structures of axial flux permanent magnet motor are introduced in detail,and the principle of stator no yoke structure and magnetic circuit characteristics are described.The overall design process of stator no yoke axial flux permanent magnet motor was studied,including the internal and external diameter design of the motor,the motor pole slot combination and winding design,etc.Combined with the main size equation of the motor and the design requirements,the main parameters of the stator no yoke axial flux permanent magnet motor were designed.Then,a 3D transient field simulation model is built according to the motor parameters,and the electromagnetic performance of the motor is analyzed in detail to verify the rationality of the motor parameters design.（2）Secondly,it introduces the causes and related theories of the loss of each part of the motor,and analyzes the influencing factors of the loss of each part according to the analytical formula.Then,the motor core materials are studied.The core materials are oriented silicon steel sheet,non-oriented silicon steel sheet and soft magnetic composite material.The influence of different materials on core loss and motor performance of fixed rotor is analyzed,and the core material scheme of fixed rotor is determined according to the design requirements of motor.Then,the effect of permanent magnet block on eddy current loss is studied,and the number of permanent magnet block is determined.（3）The basic theory of heat transfer and fluid structure coupling is described,and the factors affecting the temperature rise of the motor are analyzed.Then an air cooled structure was proposed.Based on the fluid structure coupling method,the influence law of different number and size of ventilation holes on the fluid field and temperature field of the motor was analyzed,and the most reasonable air cooled structure was selected.Finally,on this basis,the temperature distribution of each part of the motor is analyzed in detail,and the influence of wind speed on the heat dissipation capacity of the motor is analyzed.