Design and Simulation of A New Type of Axial Flux Wireless Electrically Excited Synchronous Motor

The axial flux motor has a small axial size, high power and torque density, and presents a very large application prospect in the field of limited axial space such as in-wheel motors, flying cars, and power tools. However, at present, it is mainly a permanent magnet axial flux motor. Due to the reliability of permanent magnets and low efficiency of high-speed flux weakening, its application is limited. In this paper, an axial flux electrically excited synchronous motor is proposed, and brushless is realized based on wireless power transmission. In this paper, the structure scheme of the motor including stator, rotor, wireless excitation and cooling system is given. Aiming at the problem that the stator and rotor of this kind of motor are distributed with winding excitation, the distribution of magnetic field and loss is different from that of radial motor, and the relationship between structure and electromagnetic parameters needs to be adjusted accordingly, the analytical relationship between the design parameters such as pole slot matching, inner and outer diameter ratio and shaft diameter ratio and torque and torque density is studied and established. The 3D finite element simulation model is established for simulation verification, and the law of the electromagnetic torque, torque density and other performance of the motor with the change of key parameters is revealed. Aiming at the heating problem introduced by the bilateral winding excitation of this kind of motor, a hybrid cooling heat dissipation structure of water-cooled air-cooled double circulation is proposed. Studies have shown that compared with permanent magnet motors, it has the advantages of low cost, adjustable magnetic field, and good flux-weakening speed expansion characteristics.