Design And 3D Finite Element Simulation For Hybrid Flux Modulated Permanent Magnet In-Wheel Motor

In-wheel direct-drive of the electric vehicle has some characteristics, such as the flexible layout of the drive system, the compact structure, high transmission efficiency, etc. Permanent magnet in-wheel motor has the unique advantages when used in direct-drive system of electric vehicles because of the merits of their high torque density, high power density and high efficiency, etc. Flux modulated permanent magnet in-wheel motor combines the magnetic gear and the traditional permanent magnet motor effectively, which not only has the flux modulation effect of magnetic gear, but also has the advantages of permanent magnet motor. It can be designed flexibly in terms of the structure of motor so it is suitable for in-wheel drive of the electric vehicle.In this thesis, the structures and the performances of two motors are studied, which are axial flux modulated permanent magnet in-wheel motor and amorphous core hybrid flux modulated permanent magnet in-wheel motor. And the main work is as follows:Firstly, the topology of magnetic gear is introduced and the working principle of the role of flux modulation is analyzed. And further to study the working principle of the flux modulated permanent magnet in-wheel motor so as to obtain constraint relations of the internal structures for the motor.Secondly, regarding axial flux modulated permanent magnet in-wheel motor as the object of the study, the 3D finite element simulation model of the motor is built by using Maxwell software and the simulation results in the transient field is computed. The running performances of the motor with different pole-slot combinations are studied comparatively, including the magnetic coupling characteristics of air-gap flux density and electromagnetic torque and so on. And the suitable parameters (36 slots 22/6 poles) are selected from the pole-slot combinations which are studied. Then the operation performances of 36 slot 22/6 poles axial flux modulated permanent magnet in-wheel motor which adopted amorphous core and silicon steel core respectively are calculated. Through analyzing the simulation results comparatively, it shows that the performances of the amorphous core motor are better than that of the silicon steel core motor.Finally, regarding 36 slots 22/6 poles amorphous core hybrid flux modulated permanent magnet in-wheel motor as the object of the study, the 3D finite element simulation model of the motor is built by using Maxwell software. As well as combining with the optimization method based on sweep to optimize parts of the motor structures. And the output capacities of the torque and the power are improved and it can be proved that the superiority when amorphous core hybrid flux modulated permanent magnet in-wheel motor is applied in the direct-drive system of electric vehicle.