A design method of hybrid magnetic material parallel excitation permanent magnet motor

Abstract

The invention discloses a design method for a mixed magnetic material parallel excitation type permanent magnet motor. A rare-earth permanent magnet motor is selected as a benchmarking motor, the polar trough proportioning, the stator structure, the axis length, the winding connecting mode and the air gap length of the benchmarking motor are the same as the polar trough proportioning, the stator structure, the axis length, the winding connecting mode and the air gap length of the to-be-designed mixed magnetic material parallel excitation type permanent magnet motor, the trends of magnetic circuits of the rare-earth permanent magnet motor and the to-be-designed mixed magnetic material parallel excitation type permanent magnet motor are determined, and equivalent magnetic circuit models of two motors are constructed; and the volume ranges of a rare-earth permanent magnet material and a ferrite permanent magnet material in the mixed magnetic material parallel excitation type permanent magnet motor are deduced separately, and the use mounts of the rare-earth permanent magnet material and the ferrite permanent magnet material are determined by a finite element method. Influences of theproperties and use amounts of different permanent magnet materials to the torque output capability of the motors are considered, an excitation source equivalence principle is followed, and thus, the design method is generally suitable for design of the mixed magnetic material parallel excitation type permanent magnet motor.

Description

technical field [0001] The invention relates to a design method of a motor, in particular to a design method of a parallel excitation permanent magnet motor. The permanent magnet of the parallel excitation permanent magnet motor adopts a mixed magnetic material. Background technique [0002] The rare earth permanent magnet brushless motor represented by NdFeB has the advantages of simple structure, high power density and high efficiency, so it is widely used in electric vehicles, hybrid vehicles and other fields. However, with the continuous mining of rare earth resources and the implementation of related protection policies, the price of rare earths continues to rise, which limits the large-scale development and application of rare earth permanent magnet brushless motors. Therefore, non-rare earth permanent magnet motors represented by ferrite and rare earth permanent magnet motors using mixed permanent magnet materials have become research hotspots. [0003] From the pers...

AI Technical Summary

Problems solved by technology

From the perspective of the permanent magnet magnetic circuit, the permanent magnet materials in the motor usually have two magnetic circuit structures: series and parallel. Each magnetic circuit structure has its own advantages and disadvantages: (1) The series structure has a simple magnetic circuit, but The magnetic circuits between magnetic materials have mutual influence; (2) Parallel structure, the magnetic circuits between different permanent magnetic materials are independent of each other, but the magnetic flux loss is relatively large

It is precisely because of the difference in characteristics of the two permanent magnet materials that the magnetic flux densities of the two influence each other

If the NdFeB magnetic flux density is reduced, it will not be conducive to the improvement of the permanent magnet utilization rate. If the ferrite magnetic flux density is reduced, the risk of demagnetization of the ferrite permanent magnet will increase, and even lead to Irreversible demagnetization of permanent magnets

Therefore, in the motor design process, if the ratio of the two permanent magnet materials is unreasonable, the excitation effect will be lower than the performance index of a single NdFeB permanent magnet material, which will affect the overall performance of the motor.

However, there are few studies on the amount of permanent magnet materials in the current motor design methods.

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