Study on Motor Parameters of PMSM Based on the Principle of Adjustable Leakage Flux

The magnetic field of the permanent magnet cannot be adjusted and the flux-weakening speed range of permanent magnet synchronous motor (PMSM) is small. To solve this problem, a PMSM based on the principle of adjustable leakage flux is proposed. The magnetic conductor in the rotor can move in the slot according to the rotating speed. The magnetic conductor is fixed when operates below rated speed. Once the motor speed exceeds rated speed, the magnetic conductor will slide along the slot to outward of the rotor until the forces keep balance again. The leakage flux is greater with higher speed, and the air-gap magnetic flux becomes smaller. On the basis of introducing the rotor structure, the flux-weakening principle of the motor is described. The influence of motor parameters on electromagnetic torque ripple of the motor with rated load is analyzed. The torque-speed performance is calculated. The simulation results are in agreement with the theoretical results, and the validity of wide flux-weakening range of this PMSM based on the principle of adjustable leakage flux is verified.