Characteristics Analysis of Magnetic-Pole-Shift in an Asymmetric Hybrid Pole-Permanent Magnet Assisted Synchronous Reluctance Motor

To reduce the current phase angle difference between the maximum permanent magnet torque and reluctance torque in the permanent magnet assisted synchronous reluctance motor, and increase the motor output torque at the same time, a novel asymmetric hybrid pole-permanent magnet assisted synchronous reluctance motor is proposed in this study. By asymmetrically arranging the permanent magnets and air barriers in the rotor, the permanent magnet flux-linkage is deflected. The mathematical model of asymmetric hybrid pole-permanent magnet assisted synchronous reluctance motor is established, and the relationships between the magnetic-pole-shift effect and the degree of asymmetry in permanent magnet configurations are studied. Furthermore, a multi-objective optimization process is proposed for the asymmetric rotor structure. Finite element analysis results show that the optimized motor has a 4.32% increase in output torque compared to the traditional symmetric permanent magnet assisted synchronous reluctance motor. Then, the electromagnetic characteristics of the two motors are compared and analyzed. Finally, prototype experiments are conducted to validate the finite element analysis results.