Thermal, Rotor Stress and Dynamics research for a Surface-mounted High-speed Permanent Magnet Motor

This paper provides a multi-physic fields analysis including thermal, rotor stress and rotor dynamics for a 30kW, 30000 r/min surface-mounted high-speed permanent magnet motor (SHSPMM). Firstly, this paper presents the structure parameters and electromagnetic performances of the SHSPMM. A novel cooling method is adopted to enhance the motor heat dissipation capability, with its cooling effect verified by computational fluid dynamics (CFD) analysis. Then, the rotor stress of the SHSPMM is estimated by both the analytical method and finite element method (FEM), with its influencing factors further analyzed by FEM. Finally, this paper has a further study on the rotor dynamics analysis of the SHSPMM, regarding the rotor critical speeds and corresponding bending modes. Several influencing factors concerning the rotor critical speed are also further investigated.