Study On The Novel Permanent Magnent Vernier Machine For Electric Vehicles

With the global shortage of resources and the worsening environmental pollution,electric vehicles are gradually entering the people’s perspective.Electric motor is related to the smooth operation of electric vehicles,its quality will have a great impact on the overall performance of the electric vehicles.For now,most electric vehicles achieve low-speed and large-torque output by using a combination of a motor and a mechanical gear.Such a transmission form is not only has the issue of big size and has the problems of vibration and noise which needs to be solved in many aspects.Based on the flux modulation principle,the high power density permanent magnet vernier motor with low speed and high torque characteristics that can be applied to electric vehicles is studied in this paper.In this paper,the working principle of the vernier motor——the principle of flux modulation is presented,the relationship between the number of stator poles,the number of stator flux-modulation teeth and the number of rotor poles is described,two novel motor which called rotor cage-magnet composite permanent magnet vernier motor and the vernier motor with permanent magnets on both sides of the rotor are introduced.The structure characteristic of the two motors are introduced and the two-dimensional finite element simulation model of two kinds of motors was established.The distribution of flux lines and magnetic field of the two motors was analyzed and the radial air gap flux density of the two motors was extracted and the harmonic analysis was carried out respectively.The result shows that the operation of the two motors accord with the flux modulation principle.The specific parameters such as proportion of the circumferential width of the inner and outer stator flux modulation teeth magnets and their matching ratio and the radial height of the flux modulation teeth and their matching ratio have a great influence on the performance of the rotor cage-magnet composite permanent magnet vernier motor was optimization studied,the finite element method was used to achieve the motor simulation analysis and the results verify the rationality of motor design.Based on the structural characteristics of the rotor cage-magnet composite permanent magnet vernier motor,the vernier motor with permanent magnets on both sides of the rotor was proposed.In addition to optimizing the motor parameters of the flux modulation teeth of the inner and outer stator,the pole arc coefficient of the rotor magnet and the radial height of the rotor teeth were optimized as well.The electromagnetic performance of the motor was calculated by using the finite element simulation software.The analysis results show the correctness of the theoretical research.