• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.597-599
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• 1996

This paper describes the bending traveling-wave type ultrasonic motor which generates the traveling wave by combining two standing waves with phase difference time and space. In $+20^{\circ}C{\sim}30^{\circ}C$, the USM motor operation character has represented normal condition. But the other temperature, (that is say, when long time operating condition) USM operation characteristic has abnormal condition, that is driving frequency, drive current and r.p.m is down. The recent USM has controller without temperature compensation. This study aimed at fuzzy controller which must follow the frequency at operation temperature and then r.p.m and torque increase.

• Proceedings of the KIPE Conference
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• 1996.06a
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• pp.52-55
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• 1996

This paper describes the bending traveling-wave type ultrasonic motor which generates the traveling wave by combining two standing waves with phase difference time and space. In $+20^{\circ}C$~$30^{\circ}C$, the USM motor operation character has represented normal condition. But the other temperature, (that is say, when long time operating condition) USM operation characteristic has abnormal condition, that is driving frequency, drive current and r.p.m is down. The recent USM has controller without temperature compensation. This study aimed at fuzzy controller which must follow the phase angle difference 90$^{\circ}$at operation temperature and them r.p.m and torque increase.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.119-121
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• 2006

This paper deals with characteristic analysis of switched reluctance motor including permanent magnet. First, we calculated flux density of switched reluctance motor according to position. Second, analyzed normal force and horizontal force from flux density of machine according to position. Also, analysis result compares with data that is derived through a finite element analysis (FEA), and proved validity.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.3
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• pp.496-501
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• 2009

Interior Permanent Magnet Synchronous Motor (IPMSM) produces two kind of torque that Magnetic and Reluctance torque. The permanent magnet linkage flux ${\Psi}_a$ and d-axis and q-axis inductances have an important influence on the torque characteristic of IPMSM. Thus their accurate prediction is essential for predicting performance aspect such as the torque and flux-weakening capabilities. In this paper, the influence of barrier width on the ${\Psi}_a$ and $L_d$, $L_q$ is calculated by FEM analysis. Predictions are validated by comparison the average torques, using Maxwell Stress Tensor method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.5
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• pp.632-638
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• 2013

In this study, we described voltage fluctuation characteristics of distribution line during starting and normal operation condition of the small hydro generators. Based on these theories, we scrutinized the starting and operating characteristics of induction generators installed in two small hydro power plants that is connected to the distribution line and researched necessary factors when selecting the generator type. The type of turbines and capacity of generators are different. One is below 1,000kW and the other is above 1,000kW. Two generators are tested during starting, and it acts as motor not generator at the instant that the machine is connected to the grid. After connecting to the grid, the machine rotates above synchronous speed before converting to the generator mode. Therefore the characteristic of the generator during starting is same as it of motor.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.834-836
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• 2001

This paper deals with analysis for demagnetization characteristic of a ferrite magnet line start motor using FEM. Maximum start and clock currents are calculated by transient state voltage and dynamic equation, and then, these currents are applied to FE analysis. The characteristics of motor according to partial demagnetization are analyzed from FE analytic results, and rotor shape is designed for improvement of demagnetization characteristic.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.6-8
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• 1995

This paper describes the characteristic- analysis and tile optimum design of the single-phase permanent-split condenser motor. The equivalent circuit is constructed by the symmetrical coordinate method and proved its validity by comparing with the experimental data. Then, the numerical optimization technique is applied to improve the efficiency of the motor.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.770-771
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• 2008

This paper deals with cost reduction design of a single-phase line-start permanent magnet (LSPM) motor. The characteristic analysis according to the change of quantity of permanent magnet(PM) is examined by d-and q-axis equivalent circuit. The motor parameters which are satisfied with efficiency and maximum torque are determined by the characteristic map obtained by d-and q-axis equivalent circuit analysis. And then the geometric shape design using optimization methodology is performed by finite element method (FEM).

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.727-728
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• 2008

This paper deals with characteristic analysis of permanent magnet synchronous motor with full-ring magnet. The modeling of magnetic circuit is performed analytically. And then, analytical solution for open-circuit field distribution due to permanent magnet, back-EMF and torque are derived in terms of magnetic vector potential and two-dimensional polar coordinate system. The analytical results are validated extensively by finite element analyses. Finally, we performed experiments of permanent magnet synchronous motor with full-ring magnet.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.492-495
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• 2008

As the obesity patients increase recently, breath disease such an OSA(obstructive sleep apnea) is also increasing. When the breath disease occurs, the risk comes to be high. Dependence degree the PAP(positive airway pressure) is also coming to be high. The mechanical simulator is composed cylinder, valve, ball screw and the motor that they correspond to the lung and airway, the diaphragm of the human. In order to confirm the characteristic of the motor and the valve, it accomplished an test. The simulator traces breath pattern against the normal breath and the OSA.