Research on the Air Gap Magnetic Field of Permanent Magnet Synchronous Motor for High-speed Compressor

The high-speed air compressor, which is applied for the hydrogen fuel cell (HFC), is one of the important modules. The air compressor provides the high-pressure air for the chemical reaction between hydrogen and oxygen. The high-speed permanent magnet synchronous motor (PMSM) is used to drive the high-speed air compressor. The air gap magnetic field determines the electromechanical conversion ability of the motor. In this paper, the numerical and experimental analysis of the air gap electromagnetic field between the stator and rotor was carried out. The analytic model of the magnetic flux density in the air gap was built. The analytic expressions of the magnetic flux density were theoretically derived. The analytical solution included the magnetic flux density of the cylinder permanent magnet, armature and motor load. The finite element method was used to calculate the magnetic flux density of the air gap. The comparison results between the analytic method and the finite element method showed that the fundamental wave of the analytical solution was consistent with the simulation results without considering the influence of tooth slots. The experiment of the magnetization rotor was carried out. The error of the magnetic flux density value between the experimental results and the theoretical values is about 3%. The experimental value of the magnetic flux density is slightly smaller than the theoretical value.