Design Optimization and Performance Analysis of High Torque Density and Efficiency Motors for eVTOL Applications

As the development of electric vertical takeoff and landing (eVTOL) aircraft rapidly progresses, efficient, lightweight, and high-torque-density drive motors have emerged as a critical technology. This study focuses on designing a drive motor suitable for eVTOLs, emphasizing improvements in torque density and efficiency to meet the needs of urban low-altitude operations. In response to the impact of winding cross-sectional area changes during motor optimization design, we have developed a design method for permanent magnet synchronous motors based on fixed current density, and analyzed the optimal main dimensions, air gap length, and magnet thickness of the motor. Additionally, the enhancement effects of Halbach magnets and a 30-degree phase shift arrangement on motor performance were examined. To address the strong coupling issue of stator structural parameters, a multi-objective optimization algorithm was introduced to achieve a balance between high torque density and high efficiency. The optimization results were validated through finite element simulation, with the motor’s torque density and efficiency reaching 56.5 N $\cdot $ m/kg and 93.5%, respectively. Further experimental results indicate that the prototype’s torque density is 55 N $\cdot $ m/kg with a peak efficiency of 92.5%, confirming the effectiveness and reliability of the optimized design. Moreover, simulations of a single set of three-phase winding fault conditions demonstrate the motor’s excellent fault tolerance. This research provides innovative design approaches for the efficiency and lightweighting of eVTOL motors, offering broad application prospects.