• 한국초전도ㆍ저온공학회논문지
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• 제9권3호
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• pp.21-25
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• 2007

Superconducting fault current limiter (SFCL) is attractive apparatus to reduce fault current in power grid. Since it is applied to the alternating current (AC) power line, the SFCL has losses in the normal operation. Recently, coated conductor (CC) is noticeable material employed for resistive bifilar winding type SFCL in many research groups. Bifilar structure is expected to have low AC loss by magnetic field offset as compared with the single tape structure in the same length. This paper reports about characteristic of bifilar pancake type coil for SFCL application in AC loss aspect. The bifilar coil is wound using CC with facing on HTS sides each other. Transport AC loss measurement and characteristic analysis of the bifilar coil using CC have been performed at 77K. The test results are compared with the Norris equations and the test results of non-inductively wound paralleled solenoid type coil which is suggested and tested in this group at present.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전력기술부문
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• pp.35-37
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• 2002

Most of the inhabitants living near power line complain wind noise from power line to be problems they can feel directly if there is no countermeasure to remove noise basically. Wind noise from power line happens by tower, insulators, conductor and others in their operating individually or complexly. Wind noise show us several forms like whistle, siren and bullfrog croaking as height of noise source is high and elastic wave tone with low frequency. This paper shows actual conditions and occurrence cause which may be investigated and analyzed on the wind noise, and also prepares mitigation methods and introduces a working sample to reduce a wind noise.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2020-2022
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• 2000

The cross-linked polyethylene(herein after XLPE) insulated power cable emit the methane($CH_4$)gas in the course of chemical cross-linking process. The general stranded conductor easily discharge this methane gas through the gap of each stranded wires. But the special stranded conductor that filled with semi-conducting rubber compound to prevent water penetration which is applied to water proof type of cable(22.9kV CN/CV-W), disturb the methane gas emission. The pre-mold type cable joint shall be expanded gradually by emit of gas left in XLPE insulation. For example, sometimes the corona problem outbreak on a new power distribution line, resulted from the gap between the sleeve and semi-conductive layer of cable joint. If above mentioned problem especially happened on the way of operating. We have to shut down the line and try to discharge the methane gas in cable joint. In this point, we would like to explain the mechanism of methane gas & cable joint and our test result briefly. At last, we are pleased to introduce the solution for preventing reoccurrence of this problem.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1963-1965
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• 2000

This paper deals with a problem of detecting the inner corrosion of the ACSR(Aluminum Conductor Steel Reinforced) power lines using a detector which consists of an ECT(Eddy Current Test) sensor, a constant current service, a signal processing unit, and a RF transmitter/receiver unit. The detector runs on the ACSR transmission line and inspects the corrosion of the conductor using the technic of the nondestructive eddy current test. The experimental result shows this detector can efficiently find the zinc loss in ACSR power lines.

• 대한전기학회논문지:전력기술부문A
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• 제48권1호
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• pp.16-21
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• 1999

The analysis of distribution line faults is essential to the proper protections of the power system. A high impedance fault test, which was carried in Korean electric power systems, it was found that a arcing phenomenon occurred during the high level portion of conductor voltage in each cycle. In this paper, we propose a new method for detection of high impedance faults, which uses the arcing fault current difference during high voltage and low voltage portion of conductor voltage waveform. To extract this difference, we diveded one cycle fault current into equal spanned four data windows according to the magnitude of voltage waveform and applied fast fourier transform(FFT) to each data window. The frequency spectrum of current wavefrom in each portion are used as the inputs of neural network and is trained to detect high impedance faults. The proposed method shows improved accuracy when applied to staged fault data and fault-like load.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.470-471
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• 2008

SVL is installed at underground transmission system to protect cables and insulation joint-box from overvoltages caused by lightning, switching, and line-to-ground fault. Domestic underground power system adopts cross bonding type to reduce the induced voltage at sheath, but single-point bonding is required depending the system installation configuration. SVL can be easily broken by overvoltages induced at joint-box because single-point bonding has uneffective system structure to extract fault current. ANSI/IEEE recommends Parallel Ground Continuity Conductor(PGCC) to prevent SVL breakdown. In this paper, EMTP simulation is performed to analyze effects on SVL under PGCC installation when single-line-to-ground fault occurs. The result shows that PGCC and short single-point bonding distance can reduce overvoltages at SVL.

• 대한기계학회논문집
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• 제13권4호
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• pp.697-702
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• 1989

본 연구에서는 도체의 접속 금구류의 도전 열특성을 규명하기 위한 연구의 일환으로 접속 금구류 중 접속 슬리브커넥터의 적절한 허용 전류, 통전시에 발생하는 승온 특성 및 전기 저항 특성 등을 실험적으로 구하고 접속 금구류의 설계에 필요한 도전 열특성을 실험적으로 규명하는 것을 목적으로 한다.

• 한국조명전기설비학회지:조명전기설비
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• 제13권2호
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• pp.156-156
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• 1999

This paper describes the characteristics and the criteria of electrical environmental effects produced from power system especially transmission line. Audible noise radio and TV interference, electric and magnetic inductions which are main items for optimal conductor selection as well as major contributors to the community complaint of electrical environmental problem, are surveyed and studied comparing with the criteria or the environmental protection regulation of domestic and foreign countries. As a result a domestic criteria of electrical environmental on power system was suggested.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1297_1298
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• 2009

According to previous report, aged sleeves for old transmission lines have various defect such as biased installation or corrosion of steel sleeve. These defects occupied almost 50 percent of investigated aged sleeves. These defects can cause serious accidents such as rapid increasing of sag or falling out of overhead conductor from sleeves. Moreover, the defects have been limited power capacity of transmission line. This paper study on thermal behavior of ACSR 480Rail conductor and sleeve with various defect model. The detailed results were presented in the text.

• 전력전자학회논문지
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• 제5권4호
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• pp.370-376
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• 2000

분 논문은 기존의 전력선을 이용한 전력선 반송 통선 시스템의 선호 감쇠 저하 방법을 연구한다. 제안된 시스템은 별도의 통신 선로를 설치한 필요가 없고 정보화 시대에 발맞춰 원격 검침, 자정 자동화 등 여러면에서 효율적으로 사용할 수 있다. 기존 시스템은 커패시터에 의한 반송 전류의 증기와 더불어 통신전압의 강하로 정보전달의 어려움을 가지고 있다. 제안된 시스템은 내부저향이 작고 무효전력을 공급할 수 있으며 송수신단 상호간의 저임피던스 문제가 없는 특수한 구조의 스위칭 증폭기 시스템을 가진다. 본 연구는 콘덴서 부하에 의한 PLC(Power Line Carrier) 통신 장애 문제를 해결히는데 그 목적이 있다.