Comparative Design and Analysis of New Type of Flux-Intensifying Interior Permanent Magnet Motors With Different Q-Axis Rotor Flux Barriers

In this paper, two new flux-intensifying interior permanent magnet (FI-IPM) motors owing the characteristic of L-d > L-q are proposed for extended operating speed range. The feasible approaches of realizing L-d > L-q are first discussed to emphasize rotor flux barrier design. According to the feasible approaches, interior flux barriers and surface flux barriers combined with different PM placements are adopted in these two motors. To verify the proposed approaches and the validity of motors, a comprehensive investigation and comparison between the two motors are carried out, including both electromagnetic performances and mechanical performances. By comparison, a prototype motor possessing lower torque ripple, lower magnetic saturation, wider speed range, and more robust mechanical property is manufactured and tested. The experiment results verify the characteristics of the proposed motors and the validity of the proposed approaches in FI-IPM motor design.