• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.11
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• pp.1519-1525
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• 2014

This paper presents the shape design for reducing cogging torque and characteristic analysis in Brushless DC (BLDC) motor. In this BLDC motor, ${\Delta}$(delta)-winding is applied, and in order to obtain the $60^{\circ}$ trapezoidal phase back-EMF waveform, permanent magnet shape design is carried out. And then, a method on specifying design parameters to effectively reduce cogging torque is developed. back-EMF, input voltage and input current which are analyzed by the Finite Element Method (FEM) are validated by experimental results. Also, efficiency calculations based on analysis and experimental results are performed and analyzed.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.131-134
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• 2002

The optimum design technology using combind F.E.M and eauivalent circuit is so fast and accurate that it can be applied to the optimum rotor design of an inverter-fed induction motor in high efficiency motor making industry. The optimum characteristics fer a rotor slot model of a 3 phase inverter-134 nduction motor was previously verified by a time-step F.E.M. In this paper, four verification models with the design variables near the optimum point are designed to chech whether the characteristics of a slot model presented is not less than those of the near models. The outputs of whole models are analyzed in a time-step Finite Element Method and compared in the experimental test. The economical and efficient selecting method of design variables fur the computer simulation and experimental test is presented in order to assure the optimum point.

• 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.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.8
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• pp.364-369
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• 2005

This paper deals with an automatic optimum design based on a rated output for a synchronous reluctance motor (SynRM). The focus of this paper is the motor design relative to the output power on the basis of rotor shape of a SynRM in each rated watt. And optimization algorithm is used by means of sequential unconstrained minimization technique(SUMT). The coupled Finite Elements Analysis (FEA) & Preisach model have been used to evaluate nonlinear solutions. The proposed procedure allows to define the rotor geometric dimensions according to rated watt starting from an existing motor or a preliminary design.

• Journal of KSNVE
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• v.9 no.2
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• pp.371-376
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• 1999

The purpose of this study is to identify the dynamic characteristics of a motor-die in washing machine and provide quantitative design information needed for reduction of radiated sound from the motor-die. To perform the design analysis, dynamic characteristics are identified by motor-die modeling and the availability of model is verified by experimental modal analysis. Numerical approach using MSC/NASTRAN and SYSNOISE predicted sound attenuation effects according to the change of design parameters, such as thickness, concentrated mass and rib. The numerical results due to the rib attachment showed the significant noise attenuation effects over 15 dB in the frequency range of 450∼700 Hz.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.23-32
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• 2000

The purpose of this study is to identify the dynamic characteristics of a motor-die in washing machine and provide quantitative design information needed for the reduction of radiated sound from the motor-die. To perform the design analysis, dynamic characteristics are identified by motor-die modeling and the availability of model is verified by experimental modal analysis. Numerical approach using MSC/NASTRAN and SYSNOISE predicted sound attenuation effects according to the change of design parameters, such as thickness, concentrated mass and rib. The numerical results due to the rib attachment showed the significant noise attenuation effects over 15dB in the frequency range of 450-700Hz.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.3
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• pp.303-311
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• 2012

An innovative interpretation of the per-unit interior permanent magnet (IPM) machine model known as Design Space is presented in this paper. Based on the proposed Design Space formulation, an effective computation method to predict IPM machine performance factors, such as the current and power factor in a full range of speeds, is proposed. A systematic methodology is summarized, which translates the full speed range machine design procedure into the region determination on the so-called Design Space. The effect of dc-link voltage is also analyzed in a similar manner with the current and power factor. A series of IPM motors have been designed, and a preferred motor is selected with the help of the proposed Design Space Methodology (DSM), which has the best tradeoff between the nominal voltage and the dropped voltage condition. Experiment results show that the selected motor satisfies the machine requirements and all the design constrains, such as the current and back-EMF limitations.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.5
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• pp.110-117
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• 2002

This paper proposes a optimization of the design variables of linear motor for the improvement of thrust. Especially, this paper treats the shoe, which can be good to flow of a magnetic flux in linear motor. Firstly, this paper uses a space harmonic analysis method(SHAM) based on Fourier series, for analyzing the characteristics of core type linear motor, including slot structure and shoe. And compare the magnetic flux densities of linear motor at air gap with the results of the SHAM and the Finite Element Method(FEM). Secondly, this paper uses a genetic algorithm, which is good to find the global solutions. The design variables are the pole pitch of magnet, the pitch of slot, the height of slot, the width of shoe and the width of magnet. The maximum thrust with optimum design variables is about 247 N which is improved about 16%.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.72-80
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• 2013

For the proper cooling of in-wheel motor, the cooling channel should have the characteristics which are low pressure drop and adequate cooling oil supply to motor part. In this study, the flow performance of cooling channel for in-wheel motor was evaluated and the shape of the channel was optimized. First, the pressure drop and flow distribution characteristics of the initial channel model were evaluated using numerical analysis. Also, by the result of analysis and design modification, 4 design parameters of the channel were selected. Second, using the Taguchi optimal method, the cooling channel was optimized. In the method, nine models with different levels of the design parameters were generated and the flow characteristics of each models was estimated. Base on the result, the main effect of the design parameters was founded and optimized model was obtained. For the optimized model, the pressure drop and oil flow rate were about 0.196 bar and 0.207 L/min, respectively. The pressure drop decreased by about 0.3 bar and the oil flow rate to the motor part increased by about 0.2 L/min compared to the initial model.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.2
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• pp.167-178
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• 2017

The steering wheel of a vehicle has a typical characteristic of automatically returning to its neutral state when the driver releases it. Steering returnability originated from the tire forces and kingpin moments. It is proportional to the reaction torque that is generated through the rack and column, which are dependent on suspension and steering geometry. It is also important to accurately predict and design it because steering returnability is related to steering performance. In this study, a detailed multibody dynamics model of a vehicle was designed by using ADAMS/Car and simulated for steering returnability. In addition, a tolerance analysis of the chassis system in terms of part dimension and properties has been performed in order to minimize the design parameters. The sensitivity of the selected design parameters was then analyzed via Design of Experiments(DOE). As a result, we were able to obtain the main parameters through a contribution analysis. It can be used to predict steering returnability and improve its performance, which is represented by the angle of restoration and laterality.