Enhancing Performance of Interior Permanent Magnet Motors Using Novel Stator Slot Designs

This paper presents a novel design for an interior permanent magnet (IPM) motor to reduce cogging torque and torque ripple for applications requiring high-performance variable speed drives, electric vehicles (EVs), and servo drives. The proposed design incorporates a higher number of stator slots combined with a V-shaped rotor configuration. Two types of rectangular stator slots were employed to house the rectangular stator winding, leading to a more sinusoidal radial flux distribution at the airgap and thus improving the overall torque performance. The maximum torque and per ampere (MTPA) control strategy was employed to optimize the output power for both models. To evaluate the effectiveness of the proposed design, a comparative study was conducted between the novel model and the conventional model while maintaining the same rotor configuration for both models. Different simulations were carried out using finite-element analysis under identical electrical and magnetic loading conditions. Various aspects, including radial flux density at the airgap, static torque, back electromotive force (EMF), cogging torque, d- and q-axis inductances, saliency ratio, iron loss, output torque, and torque ripple, were analyzed using 2-D finite element analysis. The results confirm that the proposed model achieves higher output torque, improved torque density, and reduced torque ripple compared to conventional designs.