• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.940-942
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• 2000

전기설비에 있어서 저압회로의 과전류 보호기기로는 배선용 차단기, 기중 차단기, 한류 퓨즈, 전자 개폐기 등이 있으며, 이중 배선용 차단기의 중요한 차단원리인 한류차단원리 및 현상에 대해 상세한 분석이 필요하다. 단락이 발생하면 상당히 큰 단락전류가 흐르게 된다. 이 단락전류를 차단하는 경우 단락전류를 그대로 흐르지 않게 하여 본래의 단락전류를 작게 제어하면 차단시의 에너지는 작아진다. 본래의 단락전류를 작게 억제하여 차단하는 방법을 한류차단방식이라 하며 이러한 기구를 한류기구라 한다. 한류차단방식을 채용함으로써 동일 치수의 차단기라면 보다 큰 단락전류를 차단하는 것이 가능하다. 여기서는 한류차단특성의 이론적 해석과 단락전류에 의한 전자기적 영향, 기계적인 영향, 열적인 영향을 설명하고 이러한 영향을 최소화하기 위한 한류차단 원리 및 방법을 설명하고 분석하고자 한다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.7 no.2
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• pp.1-12
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• 1970

In this paper, theoretical and experimental study about the light modulation at X-band(9375MHz) micro wave, using the linear electro-optic effect, has been described. The electro-optic crystal, KDP (potassium dihydrogen phosphate)is used for modulator crystals which is composed resonated modulator. Output performances of modulated wave through movable short positions are presented. It was critically respond from 2. And the output modulated intensity was compared with theoretical curve. Consequently, in spite of many problems remain yet, most promissing and more sucessful modulator configurations are compleely given.

• Journal of the Korean Institute of Navigation
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• v.6 no.2
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• pp.35-55
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• 1982

The attempt of this paper is to examine the basic theory on the analysis of the effect of a shading coil fitted to an electromagnetic contactor, and to compare experimentally the attracting force of an AC electromagnetic contactor with that of a DC electromagnetic contactor, with varying the airgap length. Equations are also proposed for calculating the AC and DC attracting force per unit consumption wattage by using the circuit constants measured from the experiment, and these calculated attracting forces are compared with those actulally measured, and then, the experimental contactor is examined in the view of its design. The calculated attracting forces are appeared to coincide well with the measured ones and the experimental contactor fitted with shading coil is revealed not so well designed for reducing the fluctuation of the attracting force.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.484-485
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• 2007

This paper describes the series-gap characteristics of transmission line arrester with switching and lightning impulse flashover test. The transmission line arrester exhibited external gap because it is must not flashover with switching impulse on the other hand it is must flashover with lightning impulse. In accordance, minimum and maximum length of series-gap was determinated with these tests. As gap length is increased flashover voltage was increased in the range of 315.4 kV~496.3 kV and negative polarity exhibited a high voltage. As a result, It was thought tat the series-gap length of transmission line arrester exhibited in the range of 580 mm~1100 mm.

• Journal of Advanced Marine Engineering and Technology
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• v.7 no.1
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• pp.40-48
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• 1983

Nowadays electromagnetic contactors are used for power on-off in various electrical loads. If the severe arc are occurred when power off, the magnetic contactor can not long run because of damage of contactor. In this paper, Authors indicate a method of how to minimize the arc when power off, Authors contrived a electronic circuit which can adjust the demagnetizing point of electro magnetic contactor, and control the demagnetizing point, utilizing our circuit, so as to occur the extinguish of arc at near the AC current zero point which is indispensibly exists. From the results of study, Authors could get confirmations the AC circuit could cut off with occurrence of mininum arc, and that possibility of extensive utilization of our method to hightension circuit.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.35-37
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• 2015

본 논문은 전력구 내 지중선에서 발생하는 상용주파수(60 Hz) 자기장을 이용한 2 W급 무선전력 수신장치를 제안한다. 제안하는 수신장치는 자성체와 구리도선을 포함하는 수신 코일, 장치의 개폐를 위한 손잡이, 직렬공진회로 및 정류기를 포함하는 부가회로로 구성된다. 수신장치는 3상 지중선 중 하나에 설치되어 전력구 내 조명 및 온습도 센서를 구동하는데 사용 가능하다. 수신장치의 자성체로는 높은 기계적 강도 및 포화 자속밀도를 가지는 규소강판 박편이 사용되었으며, 직렬공진회로를 사용하여 최대전력을 수신하였다. 수신장치의 공진회로는 3 이하의 낮은 공진계수를 가지기에 50 Hz 및 60 Hz 지중선에 범용으로 사용이 가능하다. 사용된 규소강판 및 구리선의 무게와 가격의 곱을 성능지수(Figure of Merit)로 선정하여 이를 최소화하는 설계를 수행하였다. 제작된 시작품의 무게는 약 750 g중으로 2.2 W LED부하 구동이 가능하며, 이때 지중선의 전류는 $100A_{rms}$로 가정하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.3
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• pp.175-179
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• 2022

Magnetic arc extinguishing technology is effective as an extinguishing device for low-voltage direct current (DC) circuit breakers with a resistive load of ≤4 kW. The separation distance between the magnet and the electrical contact must be shortened to increase the magnetic arc extinguishing force. However, if the magnet is installed too close to the electrical contact points, the magnet is exposed to high temperatures due to the arc current generated when the load current is cut off and the magnetism is lost. To solve this problem, the effective magnetic flux density at the electrical contact can be maintained high by placing the arc extinguishing magnet in a tandem structure with the electrical contact point between them, and the proper separation distance between the contact points and the magnet can be maintained. In addition, an electric arc extinguishing technology that emits arc energy using a series circuit of diode and resistor is used to suppress the continuous arc voltage generated by the inductive load. For the proposed circuit breaker, the breaking characteristics are analyzed through the breaking test for the DC load of the 760 V level, the load power of 4 kW, and the time constant of 5 ms, and an appropriate arc extinguishing design guideline is proposed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.4
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• pp.307-312
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• 2019

Transient earth voltage (TEV) signals propagate on metal surfaces when partial discharge (PD) occurs due to the deterioration of insulation performance in the operation of gas-insulated switchgears (GIS). A TEV sensor has advantages of high sensitivity and convenient installation for detecting PD defects. However, the TEV sensor depends on imports in domestic and detailed studies have not been conducted. In this study, a sensor was designed and fabricated by the TEV principle and its response characteristics were evaluated for detecting PD defects, which were simulated as protrusion on conductor (POC), protrusion on enclosure (POE), and free moving particle (FMP) defects. Finally, the PD-induced TEV signals were measured and phase-resolved partial discharge (PRPD) patterns were analyzed to identify the type of defect.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.368-369
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• 2008

현재 국내 중전기 시장은 시장규모에 비해 다수의 기업이 참여하고 있기 때문에, 국내 중전기 업체간 정쟁은 더욱 심화되고 있다. 따라서 국내 중전기 업체가 더욱 발전해 나아가기 위해서는 해외시장 진출 확대를 위한 수출용 전적기기의 개발이 시급하고, WTO 체제하의 시장 개방화 정책에 따른 국내외시장에서의 User의 요구에 부응하는 전력기기 개발이 절실히 요구되어 당사에서는 국책과제로써 IT 기술을 기반으로 하는 245kV Motor-drive형 초고압 GIS를 개발하게 되었다. 금번에 개발된 절연개폐장치는 변전소 자동화라는 세계적 추세에 맞추어 Bay Controller 및 전자식 변성기(NCIT)를 적용하였고, 자체 참고시험을 통해 확보된 피시품을 가지고 국제공인인증기관인 한국전기연구원(KERI)에서 IEC 국제규격에 준하여 그 성능을 검증하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.4
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• pp.37-46
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• 1998

This paper analyzes the present state of customers' effect in distribution system by momentary voltage variation. Customers are becoming increasingly concerned about the quality of electric power. Most of all, the voltage magnitude quality is very important because it can have a direct effect on customers. Especially, according to the development of automatic process, momentary voltage variations result in the shutdown of sensitive loads such as electronic equipment, computer and magnetic contactor, and so on. To analyze the shutdown rate of customers' equipments by the momentary voltage variation, we present the CVEMA curve and he cumulative CVEA curve of each load type through the experiment for the customers' sensitive equipments. Also, we have surveyed customers' opinion by the questionnaire as "Survey of Power Quality" an then the results are reported.