Design And Analysis Of Wheel Disc Permanent Magnet Synchronous Motor

Driving the electric vehicle by wheel motor directly, the energy loss of transmission system is evitable and the electric power is greatly saved. Circumrotate momentum is generated immediately by wheel motor system. The acceleration time is reduced. It is convenience to control every wheel separately. The control can be very swift. The disc permanent magnet synchronous motor (DPMSM) is a high performance axial direction magnetic motor. The DPMSM is a high energy servo motor because of its merits of high power density, small volume, light in weight, compact in structure and good dynamic characteristic. Nowadays, DPMSM is widely used in high technology field. In this paper, DPMSM is chosen as the wheel motor to drive the electric vehicle. A reasonable DPMSM is selected and designed. The magnetic field of DPMSM is simulated by finite element method (FEM)Based on the three dynamic characteristics of electric vehicle, the rated power, rated speed and other basic parameters of the wheel motor are calculated in this paper. The structure, principle and main features of DPMSM are introduced. A prototype of external rotor 4000W wedge motor is designed in detail. In order to get the concrete distribution of the motor's magnetic field, the no load field, armature field and load field of the motor is simulated separately by FEM. Due to the coreless structure of DPMSM, the field weakening effect of no load field by armature reaction is very weak. Field weakening control by adjust armature field is not fit to DPMSM. Two methods are given to fit the wide speed range requirement of wheel motor. In order to suit the high power and big torque electric vehicle, the motor can be improved to multi-disc structure, which is increased the power and torque greatly. The armature and load field of three rotors and two stators multi-disc permanent magnet synchronous is simulated in this paper. The 2D and 3D physical model are set. The effect of armature reaction in multi-disc motor is concluded.There are many advantages in wheel motor and DPMSM. Choosing DPMSM as wheel motor to drive the electric vehicle perhaps is the best method of electric vehicle driven system in the future.