This paper designs and analyzes a 130kW, 31500rpm high-speed permanent magnet motor for an air compressor. Based on the design specifications of the high-speed motor, motor materials are selected and the dimensional parameters of the motor are calculated using the magnetic circuit method. Electromagnetic field analysis is performed on the designed motor using finite element method software, along with analysis of stator and rotor losses. Then, by analyzing the motor sheath material and the permanent magnet magnetization method, the aim is to reduce internal losses, lower temperature, and improve motor performance.
Analysis of the electromagnetic field of a high-speed permanent magnet synchronous motor
The three-dimensional model of the high-speed permanent magnet synchronous motor used in the gas compressor is shown in Figure 1. The magnetic field distribution network generated by the permanent magnet of the motor is shown in Figure 2, and the vector diagram of the magnetic field lines generated by the permanent magnet is shown in Figure 3.
Figure 1
Figure 2
As shown in Figure 2, the magnetic flux lines of the permanent magnet synchronous motor are generated by the permanent magnets. The flow path of the magnetic flux lines is stator teeth, stator yoke, stator teeth, air gap, stator yoke, and stator teeth. Furthermore, the magnetic flux density in the stator yoke is significantly greater than that in the coils. The results in the figure indicate that the magnetic flux distribution and direction of the permanent magnet motor are reasonable, with relatively low leakage flux and a small leakage coefficient. The utilization rate of the permanent magnets is high, meeting the motor design requirements.
Figure 3
The arrows in Figure 3 indicate the direction of magnetic field flow. As shown in the figure, the magnetic field in the motor is generated by the permanent magnet, flows through the stator teeth, stator yoke and air gap, and finally returns to the stator teeth, forming a closed loop, which is consistent with the actual theory.
