Design And Analysis On Maltipole Surface Motor Made By Rare Earth Permanent Magnet

Aiming at the occasion where the motor has low speed, high torque and high efficiency, a kind of multipole surface rare earth permanent magnet motor is developed in this paper ,which adopts the principle of permanent magnet motor combined with magnetic field modulation magnetic gear transmission, namely VPM(Vernier Permanent Magnet) motor Principle machine. The main work of this paper is as follows:(1)Apply the basic principle of magnetic field modulation magnetic gear transmissio to the rare earth permanent magnet motor. The effects of multi - pole magnetic field coupling and cogging on the performance of the motor are studied emphatically,when the rotor is attached to a multi pole permanent magnet. Because of the stator and rotor coupling, it is not easy to directly analyze the linear mapping relationship between each variable and motor performance. Therefore, this article will analyze and simulate from the perspective of the whole.(2)On the basis of the above,the mathematical model of the slotted circular VPM motor is established by using the equivalent magnetic circuit method and the magnetic field analysis method,and the magnetic field generated by the magnetic pole is analyzed and distributed in the magnetic circuit. The specific steps to build the mathematical model are as follows:First step: Establish a magnetic pole model and analyze the magnetic field of the concentric circular radial thick and radially magnetic poles;Second step: Establish a rectangular magnetic circuit model and analyze the magnetic field and air gap flux distribution of a single magnetic field;Third step: Establish a slotless circular model and analyze the magnetic field and air gap flux distribution of a single magnetic pole in a circular magnetic field;Fourth step: Slot and multi-pole analyze of the slotless model.Establishment of Mathematical Model of VPM Motor.The establishment of VPM motor mathematical model provides a theoretical basis for multi-pole characteristics.(3) In the motor electromagnetic design work,the analysis object is the magnetic pole which is 16 pole 8 pairs of VPM motor. The important parameters such as magnetic path, magnetic flux, torque and power are analyzed when different pole ratio, same pole pair number and same pole ratio, different pole pairs. According to the process of electromagnetic layout, design the motor ratio, punch, winding,permanent magnet, electromagnetic calculation program and so on.(4) The finite element analysis method was used to model and simulate the RMxprt module and Maxwell 2D module respectively.The important performance parameters such as air gap flux, back electromotive force, electromagnetic torque and external characteristics of VPM motor under different working domain and different load are obtained.Respectively, compared with 12-slot 11-level, 12-slot 10-level VPM motor, it is found that VPM motor has the characteristics of low torque and high torque, and the design of 12-slot 8-level VPM motor is more efficient.(5) Based on the above analysis and simulation,the prototype of VPM motor is fabricated. Test the prototype in the laboratory, which includes fixed-point test,no-load back electromotive force test, temperature rise test, external characteristic test, and it is verified that the VPM prototype is consistent with the original intention of the test.In conclusion, this paper emphatically considers and analyzes the influence of the pole ratio. The finite element method is used to simulate the design of the multipolar rare earth permanent magnet motor. Finally, the prototype is produced and the output characteristics of the prototype are verified.