• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.8
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• pp.766-771
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• 2005

In this study, PD(partial discharge) signals which occur at stator coil of traction Motor are acquired these data are used for classifying the PD sources. NN(neural network) has recently applied to classify the PD pattern. The PD data are used for the learning process to classify PD sources. The PD data come from normal specimen and defective specimens such as internal void discharges, slot discharges and surface discharges. PD distribution parameters are calculated from a set of the data, which is used to realize diagnostic algorithm. NN which applies distribution parameters is useful to classify the PD patterns of defective sources generating in stator coil of traction motor.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.6
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• pp.287-291
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• 2006

Recently, various applications of permanent-magnet(PM) electric motor have been more increased. Compared with the other electric motors, PM electric motor has cogging torque which results from the interaction between PM of rotor and slot-teeth structure of stator. Audible noise and vibration is caused by this cogging torque. So, the reduction of cogging torque is main designing goal of PM electric motor. The purpose of this paper is to realize the decrease of cogging torque using new experimental design and response surface analysis which is one of the statistical methodologies.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.8
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• pp.1627-1631
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• 2011

During a routine inspection of a large pump motor at power plant, white powder was found on the surface of the stator end windings. Visual inspection and high voltage insulation diagnosis was performed to determine whether this motor is available. The purpose of this paper is to understand the insulation properties of white powder found on high voltage stator and to know prevention of insulation weakness.

• Journal of the Korean Society of Safety
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• v.23 no.4
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• pp.36-41
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• 2008

This report describes the analytical solution of back EMF for BLDC motor using numerical analysis of air gap flux density. The analysis of air gap flux density is the key to expect the performance of back EMF for the design of brushless motor. The numerical analysis and FEM analysis are performed to vary attachment of stator side or rotor side, radial flux magnetization or parallel flux magnetization, magnet arc angle in the condition of constant air gap. This results have more reliable data comparing with test result of the back EMF for 7 phase BLDC motor.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.5
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• pp.421-427
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• 2005

A closed-loop sensorless stroke control system for a linear compressor has been designed. The motor parameters are identified as a function of the piston position and the motor current. They are stored in ROM table and used later for the accurate estimation of piston position. Also it was attempted to approximate the identified motor parameters to the 2nd-order surface functions. Some experimental results are given in order to show the feasibility of the proposed control schemes for linear compressors.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.681-684
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• 2003

Piezoelectric motors have been successfully developed for various applications like autofocus drives in camera lenses and handling equipment for high-accuracy positioning. In this paper, the travelling-wave motor which used in the camera lense, using bending vibration of a ring was studied. The basic structure of the motor is same but we suggested a few parameters for considering their design. The parameter is different from sine and cosine region of the voltage of the ceramic surface, displacement according to the wave number difference, and the phase difference. Same size of ceramics and aluminium ring were used for the stator. As a result, the displacement is dependent on the wave number.

• Proceedings of the KIEE Conference
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• 2005.11a
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• pp.164-167
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• 2005

In this paper, the design and characteristics of a ${\pi}-shaped$ ultrasonic motor which is applicable to optical zoom operation of lenssystem for mobile phone are investigated. Its desi후 and simulation of performances are carried out by FEM (finite element method) commercial software. As a simulation result, by applying voltage with single phase, a combined vibration is produced at the surface of an arm of stator. The prototype of motor is fabricated and its outer size is 8*4*2 $mm^3$ including the cylindrical steel rod of 2 mm in diameter as rotor. The motor exhibits a maximum speed of 500 rpm and a power consumption of 0.3 W when driven at 20 Vpp and 64 kHz.

• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.41-43
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• 2008

This paper deals with a study on characteristic of inductance on spoke type motor. The rotor and stator is redesigned as rounding teeth of stator and pole surface of rotor. Result, a shape of air-gap is changed and the cogging torque is reduced greatly. In consequence, the inductance of spoke type motor is changed. The Finite Element Analysis(FEM) is used to characteristics.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.810-811
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• 2015

In this paper, we investigate the optimization design for a spoke type motor with the characteristics of high torque density and high-efficiency. This motor has a high output per unit volume. In order to reduce noise and vibration caused by a high cogging torque, optimization design of the rotor and stator have been conducted using both Response surface method (RSM) and Finite elements method (FEM). In this paper, we show the potential for this motor to efficiently replace existing interior permanent magnet synchronous motors (IPMSM) in a wide range of industries.

• Journal of the Korean Magnetics Society
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• v.25 no.6
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• pp.198-202
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• 2015

This s paper presents characteristics Analysis of Outer Rotor type BLDC Motor. To reduce the cogging torque and to make the high back EMF constant of the motor, Not only magnetization directions of a permanent magnet are investigated, but also a tooth chamfer of a stator is optimized. The design and analysis results are verified with experimental results.