In this paper, the outer rotor permanent magnet brushless DC motor (BLDC) with halbach magnet array was studied to im-prove the power characteristics of BLDC for drones. First, the BLDC motor applied to the currently commercial drone was se-lected as the target model and improved design was carried out. Spec generation was carried out for target BLDC model and the base model was designed and manufactured. Based on the base model, am improved design was applied using the halbach mag-net array using Response Surface Method (RSM). Applying the halbach magnet array can reduce the leakage flux and improve the efficiency by reducing the iron loss of the motor. In addition, the design for reducing the weight of the motor was carried out using RSM. It was confirmed by Finite Element Analysis (FEA) that the power characteristics of the designed improved model improved compared to the target BLDC model.

As international regulations of motor efficiency are strengthened, the line-start synchronous reluctance motor (LS-SynRM) is being studied to improve the efficiency of the electrical motor in industrial applications. However, in industrial applications, the power factor is also an important performance index, but the LS-SynRM has poor power factor due to the saliency characteristic. In this paper, the rotor design of LS-SynRM is performed to improve the efficiency and power factor. First, the barrier design is performed to improve the efficiency and power factor using the response surface method (RSM). Second, the rotor slot design is performed according to the length of bar for synchronization. Lastly, the rib design is performed to satisfy the power factor and the mechanical reliability. The final model through the design process is analyzed using finite element analysis (FEA), and the objective performance is satisfied. To verify the FEA result, the final model is manufactured, and experiment is performed.

According to International Electrotechnical Commission (IEC) 60034-1, in industrial applications not only efficiency but also power factors are important performance indexes. When comparing line motor to induction motor (IM), a line-start synchronous reluctance motor (LS-SynRM) has a high efficiency but a low power factor than that of IM. In this article, the analysis and design of LS-SynRM are carried out considering the rotor slot opening and bridges for improving the efficiency and power factor. The reference machine is selected with a 2.2 kW IM, and the performance of the reference model is analyzed based on finite element analysis (FEA). To analyze the effect of rotor slot opening and bridges, an optimal model of LS-SynRM is designed through a two-step design process. First, the design of rotor slot for synchronization is carried out, and second, the design of barriers using the response surface method (RSM) is carried out under the same conditions of the stator size of IM. Based on the basic model, the performances of LS-SynRM are analyzed according to the slot opening and bridges. Furthermore, the parametric analysis is carried out and the final model is designed considering the efficiency and power factor based on the design parameters. Finally, the final model is manufactured, and the experiment is carried out to verify the FEA result.

In order to improve the efficiency, a line-start synchronous reluctance motor (LS-SynRM) is studied as an alternative to an induction motor (IM). However, because of the saliency characteristic of SynRM, LS-SynRM have a limited power factor. Therefore, to improve the efficiency and power factor of electric motors, we propose a line-start permanent magnet assistance synchronous reluctance motor (LS-PMA-SynRM) with permanent magnets inserted into LS-SynRM. IM and LS-SynRM are selected as reference models, whose performances are analyzed and compared with that of LS-PMA-SynRM using a finite element analysis. The performance of LS-PMA-SynRM is analyzed considering the position and length of its permanent magnet, as well as its manufacture. The final model of LS-PMA-SynRM is designed for improving the efficiency and power factor of electric motors compared with LS-SynRM. To verify the finite element analysis (FEA) result, the final model is manufactured, experiments are conducted, and the performance of LS-PMA-SynRM is verified.

In this paper, a design of six-phase surface inset permanent magnet synchronous machine (SIPMSM) with the open slots is performed considering the power factor and torque ripple. Because of the reluctance torque component by the q-axis core thickness of rotor, a surface inset permanent magnet synchronous machine (SIPMSM) has the high torque density but the large torque ripple. To overcome the large torque ripple, there are the various design method. In case of SIPMSM with the open slots, the tapering of shoe and the notch of stator and rotor cannot apply the tapering is applied to magnet, but the torque density and power factor decrease because the linkage flux by the permanent magnet reduce. Therefore, the thickness of q-axis core and tapering magnet has the trade-off between the performance and torque ripple. In this paper, the characteristic according to the q-axis core thickness and tapering magnet is analyzed based on a finite element analysis (FEA). Furthermore, the optimal design is proposed using the performance map based on the tapering of magnet and q-axis thickness of core. For the design of a basic model, pole-slot combinations are compared with the torque of SIPMSGM according to the current phase angle. Considering the performance, the basic SIPMSGM is selected for the optimal design. Based on the basic SIPMSGM, the optimal design is performed based on the optimal design parameters considering the power factor and torque ripple.

This paper establishes an analysis method of permanent magnet assistant synchronous motor (PMA SynRM) with asymmetric barrier. In a general motor analysis method, the inductance is calculated using the dq-axis vector diagram. In addition, the characteristics of the motor are analyzed by separating the mag-netic torque and the reluctance torque. However, in an asymmet-ric motor, the magnetic neutral plane (MNP) is shifted because the magnetic permeance is asymmetric. Therefore, it is difficult to analysis the characteristic of the asymmetric motor because it in-volves errors applying the general analysis method. In this paper, the magnetic property of the asymmetric motor is analyzed and the analysis method of asymmetric motor is proposed. To verify the proposed analysis method, PMA SynRM is designed as a conventional model. Furthermore, the magnetic torque and reluc-tance torque are separated through the proposed analysis meth-od. The validity of the proposed analysis method is verified through finite element analysis (FEA) and manufacture of the conventional model.