Analysis On Magnetic Field And Eddy Current Loss In The Disk Coreless Permanent Magnetic Synchronous Motor

Axial flux disk coreless machine, contrasting with the traditional radial flux machine, has many obvious advantages: its structure is simple, the expense of machining and assembling is lower, its running is steady, no excitation current, and the efficiency and the power is enhanced. The development trend of the disk machine is permanent magnet machine. The rare earth permanent material is the first selection to make the permanent magnet in the machine. In our country, the disk permanent magnet machine has been developed. But the machine is being trial-manufacture. And there are many problems to be solved.The paper mainly analyses the air gap magnetic flux density of the machine, and studies every factor influencing the air gap magnetic flux density of the machine. The main content just as the list below:First, the development and application of PMSM are briefly reviewed. The performance of the permanent magnetic material and selection, the design principle of the magnetic circuit, the theory of the electromagnetic field, and the FEM software are introduced.Second, through the combination of the electromagnetic field, the FEM software and the structure, the paper designs about twenty FEM programs, which constitute a software package aiming at the calculation of the magnetic field of the disk permanent magnet machine. Through the software package, the paper analysis the magnetic flux density in the air gap.When describing the three-dimensional distribution of the air gap magnetic flux density, the data should be exported from FEM software, and then the other math plotting tool is used to plot the three-dimensional magnetic flux density figure. For the problem of compatibility of the data format, the data format, exported from the FEM software, should be coordinated into the requirement of the other math tools. For the large quantities of the data, the paper designed a Vb program to handle the data automatically.Third, according to the software package, the paper made a series of analysis of the air gap magnetic flux density, including three-dimensional open domain magnetic analysis, the influence to the magnetic flux density of the permanent magnet thickness, the analysis of the magnetic flux density when the variation of the width of the permanent magnet, the analysis of Halbach array of different angle and the analysis of the air gap magnetic flux density at different radiation. All the analysis above offered a foundation of the designation of the permanent magnet in the disk coreless machine.Last, according to the analysis of the magnetic flux density of the disk machine, the paper presents an optimization designation of the machine. Then, the modeling and analysis is made. The result of the analysis indicates that the optimization designation could achieve more ideal sine wave. Furthermore, the eddy current loss is analyzed qualitatively. And the analysis indicates that the eddy current loss could be reduced largely.