• 전기학회논문지
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• 제63권3호
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• pp.418-424
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• 2014

A large number of wire rope has been used in various industries such as cranes and elevators. When wire used for a long time, wire defects occur such as disconnection and wear. It leads to an accident and damage to life and property. To prevent this accident, we proposed a wire rope fault detection system in this paper. We constructed the whole system choosing the leakage fault detection method using hall sensors and the method is simple and easy maintenance characteristics. Fault diagnosis and analysis were available through analog filter and amplification process. The amplified signal is transmitted to the computer through the data acquisition system. This signal could be obtained improved results through the digital filter process.

• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1345-1351
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• 2013

Variable iron loss as function of current phase angle of Interior Permanent Magnet Synchronous Motor(IPMSM) was calculated through Curve Fitting Method(CFM). Also, a magnetic flux density distribution of iron core according to current phase angle was analyzed, and an iron loss calculation was performed including harmonic distortion. The experiment was performed by production of non-magnetizing model for the separation of mechanical loss, and the iron loss was calculated by the measurement of input using power analyzer and output power using dynamometer. Some error was generated between experimental results and calculation value, but an iron loss diminution according to current phase angle followed a same pattern. So, errors were generated by measurement, vibration, noise, harmonic distortion loss, etc.

• Journal of Electrical Engineering and Technology
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• 제8권5호
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• pp.1221-1226
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• 2013

In this paper, the equivalent circuit for the efficiency calculation by precise estimation of the linkage flux, inductance and iron loss resistance was calculated accurately. In addition, the driving characteristics according to the current phase angle are analyzed and the maximum efficiency point is calculated. And then, analyzed and experimental values of the efficiency were compared. So, causes of error were expected to be vibration and noise by harmonic distortion of the voltage and current, and mechanical loss of dynamometer. In addition, the driving characteristics according to the current phase angle are analyzed and the maximum efficiency point is calculated.

• Journal of Astronomy and Space Sciences
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• 제15권2호
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• pp.437-447
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• 1998

한반도의 지도 제작을 주임무로 1999년에 발사될 다목적 실용위성의 궤도 오차를 GPS 항행 해와 지상 안테나의 추적 데이터를 이용하여 분석하였다. 측정 데이터의 잡음과 모델 링의 오차를 고려하여 최소 자승 방법으로 궤도 결정과 예측 오차를 시뮬레이션 하였다. 측정 데이터의 잡음은 단기간 오차의 주 요인이 되며, 태양 플럭스의 불확실성으로 인한 오차가 궤도 예측 오차에 가장 크게 작용함을 알 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.77-79
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• 2007

In previous structure of single phase LSPM, there is large torque ripple that makes a noise and a vibration by a distortion of flux distribution in air gap. By this reason, the single phase LSPM is not accepted home applications. So, in this paper, we propose new structure of single phase LSPM(Line Start Permanent magnet Motor). The proposed model is reduced a torque ripple about a half than previous model.

• Journal of Mechanical Science and Technology
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• 제17권7호
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• pp.1083-1094
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• 2003

This study represents an assessment of the phase-Doppler technique to the measurements of dense droplet laden jet. High-pressure injection fuel sprays have been investigated to evaluate the use of the Phase-Doppler anemometry (PDA) technique. The critical issue is the stability of the phase-Doppler anemometry technique for dense droplet laden jet such as Diesel fuel spray in order to insure the results from the drop size and velocity measurements are repeatable, consistent, and physically realistic because the validation rate of experimental data is very low due to the thick optical density. The effect of shift frequency is minor, however, the photomultiplier tube (PMT) voltage setting is very sensitive to the data acquisition and noise in dense droplet laden jet. The optimum PMT voltage and shift frequency should be chosen so that the data such as volume flux and drop diameter do not change rapidly.

• 한국가구학회지
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• 제25권2호
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• pp.122-128
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• 2014

Recently, many studies have conducted to satisfy a physical need of human between environment of light on space, so an atrium structure has been applied to cultural complex. However, this structure brings about many problems such as overheating in summer, excessive vertical temperature differences, condensation, diffusion of noise, effect of echo, and withering landscapes. Especially, in this research, thermal comfort by difference of vertical temperature in the space of atrium and the optical characteristics of glass skins of the atrium could be remarkably effected by solar flux entering indoors.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.296-298
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• 2003

At the water supply field, high voltage induction motor is main facility of a load equipment. The motor is often out of order and its noise, generated heat, loss etc occured occasionally. especially, transmission motor for flux control generates an amount of the harmonics then have a bad influence upon the electric power system. In this study, to analyze the total harmonics distortion of the water supply field receiving high voltage, the harmonics measured and analyzed using the PQA(Power Quality Analyzer) according to the electric power system and electrical load and the reduction method presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.22-24
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• 2005

This paper is intended to introduce a set of static and dynamic experiments for a better characterization of the linear permanent magnet oscillatory machine. The experiment have been peformed on two prototypes; one with buried permanent magnets with flux concentration while the other with surface permanent magnets. Though the testing arrangement allows for it, temperature, noise and vibration have not been in this paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.737-741
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• 1987

The induction motor is represented by nonlinear equations whose parameters are changing with respect to the slip-frequency, temperature, etc. The slip-frequency is effected by unknown load which is difficult to estimate on-line. Astable vector controller is designed with direct MRAC to improve the quality of the transient response. The unknown load is considered in this speed controller design, and tested by simulation. Also a flux controller is designed and tested to reduce the audible noise in this paper.