Consequent Pole Permanent Magnet Synchronous Motors (CP-PMSM) have received attention because they can reduce the amount of permanent magnets used. Due to structural features, the magnetic flux of the air gap is imbalanced. Furthermore, torque ripple increases due to even harmonics of back electromotive force. In this paper, We propose an asymmetric design method to reduce torque ripple and magnet usage in consequent pole (CP) surface permanent magnet synchronous motor (SPMSM). First, the iron and magnet pole areas are selected asymmetrically to increase torque and reduce torque ripple. Second, the N pole of the CP-SPMSM(CP-Npole) and the S pole of the CP-SPMSM(CP-Spole) are combined in the axial direction to reduce the even harmonics of back electromotive force. An air gap is inserted between the two CP-SPMSMs to reduce axial leakage caused by the combination of opposing poles. Then, the location and axis length of the iron pole are designed asymmetrically. Torque ripple is further reduced by reducing the harmonics multiple of 6 of the back electromotive force. Finally, we compare the electromagnetic characteristics of SPMSM and CP-Npole with the proposed model. The proposed model reduces torque ripple and increases torque per permanent magnet usage. We performed the finite-element analysis in 3D to analyze all models’ axial electromagnetic characteristics.

Surface permanent-magnet synchronous motors (SPMSMs) have been widely adopted for ship propulsion due to their high power density and efficiency. However, conventional three-phase open-slot SPMSMs struggle to balance high efficiency with reductions in cogging torque and torque ripple. This paper proposes a design of an SPMSM with a six-phase winding configuration and a chamfer-shaped permanent magnet to reduce cogging torque and torque ripple. Electromagnetic performance is evaluated through finite element analysis (FEA). A reference three-phase interior PMSM and three-phase SPMSMs with different magnet shapes are first compared to identify a suitable basic design. Based on the basic machine, three pole–slot combinations for the six-phase winding are analyzed, and the most efficient configuration is selected. A final model is designed to minimize cogging torque and torque ripple for the chamfer-shaped permanent magnet. Finally, the effectiveness of the final model is validated through FEA by comparing its performance with that of the reference model.

Although dual-vector model predictive current control (MPCC) provides fast dynamic response and a compact control structure, it still relies exclusively on the inverter’s eight basic voltage vectors (VVs). This dependence leads to substantial computational load as well as pronounced current ripple, ultimately limiting steady-state performance. To overcome these limitations, this paper presents an enhanced MPCC strategy for surface-mounted PMSM drives. First, a simplified optimal-vector selection framework is introduced to reduce the computational complexity of conventional MPCC, achieving nearly a 50% reduction in execution time. Second, a refined cost function incorporating both soft and hard constraints on current variation is developed to suppress rapid current changes and achieve near zero-error tracking. Finally, a duty-ratio allocation method based on the deadbeat principle is derived, enabling more effective utilization of the selected voltage vectors and further improving control performance. The proposed method is validated through theoretical analysis and simulation studies and is experimentally demonstrated on a 1-kW PMSM platform, confirming its effectiveness and superior steady-state and dynamic performance.

Electric power steering (EPS) motors require low torque ripple, low cogging torque, and smooth torque output to ensure precise control and driving comfort. However, consequent pole permanent magnet synchronous motors (CP-PMSMs), although advantageous in reducing permanent magnet usage, exhibit an imbalanced magnetic flux distribution due to the iron poles, resulting in even-order harmonic components in the back electromotive force (BEMF) and significant torque ripple. In this paper, a rotor pole arrangement for CP-PMSMs is proposed to improve torque characteristics for EPS applications. Symmetric and asymmetric pole arrangements are introduced to modify the magnetic flux distribution and suppress harmonic components generated by the iron poles. In addition, the iron pole arc ratio is selected as a key design variable and analyzed for each model to achieve low torque ripple while maintaining torque performance. The electromagnetic characteristics of the proposed structures are evaluated using finite element analysis under identical operating conditions. The results show that the torque ripple of the proposed models is reduced by approximately 33.3%p and 34.1%p compared with the conventional CP-PMSM, and the cogging torque is also significantly reduced. Although average torque decreases, overall torque characteristics improve due to reduced torque ripple and harmonic components. These results demonstrate that the proposed rotor pole arrangement effectively enhances torque quality in CP-PMSMs without increasing axial length or requiring three-dimensional analysis.