Design Of A New Type Of Axial Flux Permanent Magnet Machine

Compared with radial flux permanent magnet machine,the axial flux permanent magnet machine using less core material,with higher torque density and higher efficiency.Therefore,the axial flux permanent magnet motor is more suitable for the application of compact axial space and high axial torque density.With the progress of new magnetic materials,as a new material,Soft Magnetic Composite(SMC)materials has the advantages of Magnetic isotropy and low core loss at high frequency.According to the characteristics of axial magnetic flux permanent magnet machine and the characteristics of SMC material,an axial magnetic flux permanent magnet machine for electric vehicles with 3D magnetic circuit,high power density and high efficiency is designed,which has the advantages of compact structure and good flux concentrating ability.At the same time,due to the low inductance of the axial flux permanent magnet machine,the constant power speed range of the machine is low,therefore a new mechanical flux weakening method applied to the axial flux permanent magnet machine is proposed and intensive studied.For the new type of axial flux permanent magnet machine designed in this paper:Firstly,the magnetic circuit model of the designed new axial magnetic flux machine is established,the topological structure of the machine is introduced,the specific size and material selection of the machine are determined,and the static magnetic field simulation is carried out on the established machine model through the finite element simulation software to verify that the designed machine has a good flux concentrating ability.The yokeless and segmented armature machine of the same volume is used as the standard for comparison.At the same time,the machine models of Nd Fe B permanent magnet and ferrite permanent magnet were built for comparative analysis.Secondly,the parameters of the four types of machine models are optimized,and comparing the effect of different size of stator windings,stator boots and stator teeth on average torque,as well as comparing the effect of different size of permanent magnets on the torque ratio weight and torque ratio material cost,so as to obtain a higher torque density.Finally,the finite element simulation method is used to compare and analyze the performance of the four kinds of machines studied in this paper,including the permanent magnet flux,reverse electromotive force,torque,power factor,loss and efficiency,etc.For the mechanical flux weakening structure designed in this paper:Firstly,a magnetic circuit model is established for the mechanical weak magnetic device designed for single-stator single-rotor machine.Secondly,the topological structure,size and material selection of the machine are introduced,and the static magnetic field simulation of the two pole-slot ratio machine models is carried out by the finite element simulation software,which verifies that the designed machine has good flux weakening speed regulation performance.Finally,the performances of the two pole-slot ratio machines are compared and analyzed,including the permanent magnet flux,reverse electromotive force,inductance,speed regulation performance,torque,loss and efficiency,etc.