• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.10
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• pp.1397-1402
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• 2013

This study researched cause of resonance noise for BLDC motor used in the refrigerator. it is difficult to measure dynamic characteristics for small sized fan & rotor system with conventional excitation method. Therefore this study performed electric exiting method and natural frequency method using microphone instead of conventional excitation and showed validity of these methods. Study result showed that tortional vibration frequency of fan & rotor system and natural bending frequency of the fan were matched with exciting frequency of BLDC motor caused by commutating ripple torque. And this frequency match caused resonance of the system. The study analyzed main parameters of this phenomenon and suggested alternative solution.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.688_689
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• 2009

This paper presents a multi-objective optimal design process for an in-wheel permanent magnet synchronous motor (PMSM) for high performance. In order to improve the characteristics of the PMSM such as the cogging torque, torque ripple and the back-EMF, the modified Taguchi method and the response surface method (RSM) are utilized. In addition, results of the proposed model are compared with the initial design and it is verified by 2D FEM.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.824_825
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• 2009

This paper deals with the characteristics of SPMSM for hydraulic actuator according to the slot number. As a design variable, slot number affects the winding configuration and this leads to the total variation of motor characteristic. Therefore number of slot should be cautiously determined. Three SPMSMs are designed and THD of back emf, cogging torque, and torque ripple are compared. Among three SPMSMs, 36slots with 12 pole is chosen for further development considering motor characteristics and manufacturing.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.196-201
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• 2008

This paper is about electromagnetic vibration source in outer rotor type of BLDC motors. Experiments are carried out with three pole-slot combinations which are 6 slots, 12 slots, and 24 slots with 4 poles rotor. According to results, vibration sources separate into electromagnetic and mechanical factors. Using the finite element method (FEM), It is analyed that vibration characteristics of electromagnetic source in each type. This paper shows electromagnetic sensitivity to vibration, and introduces necessary point in lower vibration motors. Also rotor balance is important to prevent uneven distribution of magnetic flux between rotor and stator.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.1
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• pp.51-56
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• 2013

With the active development of hybrid electric vehicle (HEV), the application of interior permanent magnet synchronous motor (IPMSM) has been expanded. As wide driving region of IPMSM for electric vehicle (EV) traction motor is required, many studies are conducted to improve characteristics of a motor in both low and high-speed driving regions. A motor in high-speed driving region generates (produces) large stress to the rotor. Thus, the rotor needs to be designed considering the mechanical safety. Therefore, in this paper, we conducted stress analysis and electromagnetic analysis to determine the centerpost's distance which is considered important during the design of IPMSM for EV traction motor in order to secure mechanical safety and satisfy specifications of output requirement.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.43-45
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• 2004

This paper presents the optimal design of a brushless DC motor(BLDC) keeping the average torque and cogging torque of the initial model while minimizing the volume of magnet pole. Experimental design method and evolution strategy technique are performed for the shape optimization. The presented optimal designs show the both methods have the almost same result.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.862-863
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• 2008

This paper presents the improvement of dynamic characteristics in Interior Permanent Magnet (IPM) type BLDC motor with notch. The notch is applied on the surface of the rotor to reduce the cogging torque and to improve dynamic characteristics. The current, inductance and torque of initial model and optimal model are analyzed by FEA. The validity of improved dynamic characteristics is confirmed.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.680-681
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• 2015

This paper proposes a comparative study of dual-airgap flux switching permanent magnet (FSPM) and spoke-type interior permanent magnet (S-IPM) machines equipped with phase-group concentrated-coil (PGCC) windings. Both of the investigated machines are the same size and material amounts which are compared at the same operating conditions. All the relevant machine performance including back electromotive force (EMF), cogging torque, and electromagnetic torque are analyzed by a 2-D time-stepping finite element method (FEM).

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.3
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• pp.241-247
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• 2011

This paper is intended to improve efficiency of two-phase BLDC motor using analytical and statistical methods, and then the stability of the starting for the designed model is investigated. The characteristics of the motor according to magnetization directions of permanent magnet are analyzed through the analytical method, and design variables that affect the efficiency are selected. Preliminary optimal design is performed using the analytical method with the design variable. The RSM (Response Surface Method) based on the FEA (Finite Element Analysis) is applied to complement errors of the analytical method. As a result, the optimal design is determined. Finally, the stability of the starting for the optimal designed model is evaluated by analyzing cogging torque, and it is verified through the FEA.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.611-613
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• 2000

Rotor eccentricity exists extensively in BLDC motors because of manufacturing imprecision or bearing defects. In this paper, magnetic fields of a BLDC motor with static rotor eccentricity are analyzed by the time- stepping finite element method. Torque ripple, cogging torque, winding current, counter-em! and unbalanced magnetic force characteristics are obtained. These results are compared with those of a non-eccentric BLDC motor.