Mass Optimization Method of a Surface-Mounted Permanent Magnet Synchronous Motor Based on a Lightweight Structure

To solve the problem that the propulsion motor of the solar-powered aircraft is difficult to meet the high-torque-density requirement, the mass optimization method of a surface-mounted permanent magnet synchronous motor (SPMSM) based on a lightweight structure is proposed in this paper. According to the motor load generated by propeller, the strength and stiffness analytical models of the mechanical structure are established. By correlating the mechanical dimensions with the electromagnetic dimensions, a full-scale parametric model of SPMSM is obtained. A 4kW and a 167W SPMSMs are designed based on the parametric model. Analysis results show that with the increase of the ratio of motor diameter to length, the motor mass firstly decreases and then increases, and there is a minimum value. The validity of the lightweight structure and analytical models are verified by the finite element models (FEM) and prototypes.