Optimal Design of Fractional Slot Number Using Response Surface Method on the Cogging Torque and Unbalanced Magnetic Pull Reduction in Permanent Magnet Machine

This study investigates the optimal design for addres both cogging torque and unbalanced magnetic pull reduction. At the magnet edge, the authors employed a multiple combination method, specifically a slotting and pole arc optimization technique. These issues contribute to a decline in machine performance in various applications due to the interaction of several factors, including materials, structure, and manufacturing processes. The study investigates methods to enhance cogging torque and reduce unbalanced magnetic pull by examining the initial stages of design, beginning with the selection of the material and magnetic structure. Compared to the old structure, this new design for a permanent magnet machine can reduce cogging torque by about 98.68% and unbalanced magnetic pull by 28.57%. It achieves this by combining two steps: slotting and pole arc optimization at the magnet edge.