• Electronics and Telecommunications Trends
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• v.5 no.4
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• pp.12-41
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• 1990

본고는 자연적인 현상의 번개와 같은 서어지로 인해 야기되는 각종 위해(Harm)로부터 전기통신회선을 보호하기 위해, 세계 각국에서 규정하고 있는 서어지 기술기준의 동향을 분석하여 우리나라가 대처해 나가야 할 방향을 찾고자 한 것이다.

• 전기의세계
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• v.27 no.6
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• pp.21-29
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• 1978

American Electric Power회사에서 건설항 미국최초의 A.C 765kV송전선과 변전소에서 일련의 159회에 달하는 개폐시험과 기타시험을 상업운전에 앞서 시행하였다. 여기서 얻은 광범위한 Data, 즉 여러 조건하에서의 개폐서어지전압, 기기특성, 과전압억제방법, Radio장해 및 가청잡음등에 대해 설계치와 비교검토하였으며 그 결과를 여기에 제시한다.

• Journal of Korea Water Resources Association
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• v.30 no.6
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• pp.769-776
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• 1997

The behavior of surge induced in the discharge system of the thermal power plants by the sudden stop of cooling water pump is analyzed using the numerical model developed by Yoon and Lee (1997). Various effects, which are ignored earlier, such as discharge from internal system, air chamber and air inlet of seal well, monholes, open channel and sea are included. These effects of the surge behavior are systematically analyzed. Especially, the surge control effect and air pressure change in the air chamber associated with the area of air inlet are presented for easy application in practice.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.10
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• pp.118-125
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• 2007

The lightning surge and switching surge could be injected to the underground distribution line through the riser pole in the mixed distribution line of overhead and underground. These surges travel along the cable and are reflected at the end of cable. It can be doubled and affecting underground distribution facilities. It was made a underground distribution model representing KEPCO's distribution system. It was measured propagation characteristics by applying lightning surges to this underground distribution model. Meanwhile, this system was simulated with ATP-EMTP and compared these real test results md tuned up the EMTP parameters. EMTP simulation results showed that accord with real test result by adjusting the cable insulation permitivity, arrester characteristics, surge wave shape.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.10
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• pp.84-88
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• 2008

This paper deals with the part of the surge protection method of the underground distribution system in Korea using arrestors by simulating with ATP-EMTP(Electro-Magnetic Transient Program) based on the "A Study on the Surge Propagation Property of Underground Distribution Cables by Field Tests" which was published in 2007. Although domestic underground distribution system is protected by arrester which installed at a riser pole, we need to additional protection method because lightning surge can be doubled and affect underground distribution facilities when it is injected into the mixed distribution line of overhead and underground through a riser pole. In this paper, it is proposed that scout method that arresters are attached to the sides of a riser pole is better than developing of a elbow arrester on a viewpoint of economics and maintenance, because of the situation of the domestic underground distribution system.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.2 no.2
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• pp.91-97
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• 1991

낙뢰 현상은 오랫동안 인류에게 신의 분노와 같은 것으로 여기며 신비스럽고 두려운 자연현상 중의 하나로 생각했으나, 자연과학의 발달로 요즈음은 대기중의 전기방전으로 자연스럽게 받아들인다. 그러나 최근 문제가 되고 있는 EMI/EMC 관점에서 보면 낙뢰 현상은 EMI를 일으키는 대표적인 발생원으로서 여전히 두려움 의 대상이다. 본 기술 해설난에서는 먼저 낙뢰시 발생되는 전자파의 세기와 파형에 대해 살펴보고, 이러한 전자파에 의한 EMI 문제 사례로서 전화가입자 선로에 유기되는 낙뢰서어지로 부터 교환기 보호라는 관점에 관해 기술하기로 한다.

• 전기의세계
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• v.45 no.4
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• pp.5-12
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• 1996

지금까지 변압기의 유지보수는 일상순시와 전력설비를 일정기간 사용함에 따른 정기점검에 의하여 불량개소를 발견하고 보수하는 일정주기에 따른 예방보수를 하였으나, 경제적인 유지와 신뢰성 있는 전력공급을 위하여 변압기의 상태를 점검하여 정비하는 상태점검으로 전환하고 있다. 따라서 최근에는 변압기의 이상징후를 운전상태(on-line)에서 상시 감시하여 장래에 일어날 사태 등을 예측하고 그것이 치명적이기 이전에 처리하는 예측보전기술 중심으로 변하고 있다. 변압기의 내부이상을 진단하는 방법으로는 부분방전법, 절연유의 특성시험 및 가스분석법, 역률측정법, 저압서어지 시험법 등이 있으나, 진단방법의 특성 및 신뢰성을 고려할 때, 어느 한 방법으로는 불충분하므로 각종 진단 결과의 종합분석이 필요하다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.591-595
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• 1997

In analysis of piping vibration of petrochemical plant, the forcing functions mainly depend upon the equipment working mechanism and vibration resources in the piping systems. In general, harmonic function is used for the system with rotary equipments. Mechanical driving frequencies, wave functions, and response spectrum are used for reciprocating compressors, surge vibration of long transfer piping, and seismic/wind vibration, respectively. In this study, for the spray injection case inside the pipe, forcing function was modeled, in which two different fluids are distributed uniformly. To confirm the results, the scheme used for the forcing function was applied for real piping system. The vibration mode of the real system was consistent with the 4th mode obtained by simulation using the forcing function formulated in this study.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1904-1906
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• 1996

Transient voltage distribution tests are carried out to evaluate effects of a high frequency oscillating voltage generated in a superconducting magnet as a result of the arc discharge extinction. Especially, the effects of temperature and conduction state of the magnet conductor on surge behavior are carefully investigated. Based on the results of simulation tests, it is shown that internal voltage waveforms are influenced by its transmission along the superconducting wire and reflection at the terminal and that attenuation process of the waveforms depends considerably on the conductor resistance which decreases with lowering the temperature.

• Journal of the Korea Society for Simulation
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• v.10 no.4
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• pp.1-10
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• 2001

For the simulation of piping vibrations in petrochemical plants, forcing functions mainly depend upon the equipment working mechanism and vibration resources in the piping systems. In general, harmonic function is used to simulate rotary equipment. Mechanical driving frequencies, wave functions, and response spectrum are used to simulate reciprocating compressors, surge vibration of long transfer piping, and seismic/wind vibration, respectively. In this study, the general suggestions for forcing functions were reviewed and proposed the forcing function to simulate the spray injection system inside the pipe in which two different fluids are distributed uniformly. To confirm the results, the scheme was applied for a real piping system. The vibration mode of the real system was consistent with the 4th mode (26.725 Hz) obtained by simulation using the forcing function presented in this study.