A Dual-Permanent-Magnet Machine With Asymmetric Stator Teeth-Tips

Dual-permanent-magnet machines (DPMMs) have attracted increasing attention due to their merit of high torque density. Nevertheless, DPMMs suffer from a low permanent-magnet (PM) utilization ratio owing to large PM consumption. To improve the situation, this article presents a DPMM with asymmetric stator teeth-tips, termed AST-DPMM. The key of the proposed design is to arrange wide- and narrow-stator teeth-tips alternatively. By building an analytical model of the AST-DPMM, the impact of asymmetric stator teeth-tips is investigated. It is found that asymmetric stator teeth-tips can enhance the working harmonics by generating new magnetomotive force (MMF) harmonics and permeance harmonics. Hence, it can achieve high torque density and improve the PM utilization ratio simultaneously. The performance comparisons together with other machines are conducted to evaluate the investigated AST-DPMM. Finally, a prototype of the AST-DPMM is fabricated, and the experimental testing is conducted to verify the proposed ideas.