• Title/Summary/Keyword: Electric Wires

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A study on the Stability of Bi-based Superconducting Wires cooled by a Cryocooler (저온냉동기로 냉각된 Bi 계 초전도선재의 안정성 연구)

  • 이호진;홍계원
    • Electrical & Electronic Materials
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    • v.10 no.4
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    • pp.320-326
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    • 1997
  • The stability of Bi-based superconducting wires cooled by a cryocooler was studied by considering the temperature dependency of critical current and electrical resistivity. The critical current measured in 23 K was about 7 times higher than that measured in liquid nitrogen of 77 K. The stability behavior of Bi based multifilament wires subjected to a thermal disturbance, which was simulated with a electric heater, was investigated by measuring the variation of voltage drop with time. Current sharing was occurred, and recovery to superconductivity was measured in the wire after removing heater power.

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Calculation of shielding range using shield wires in Myanmar 500kV Substation (차폐선을 이용한 미얀마 500kV 변전소 차폐보호범위 계산)

  • Park, H.S.;Kim, T.Y.;Cho, Y.S.;Park, C.S.;Joo, S.H.
    • Proceedings of the KIEE Conference
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    • 2005.11b
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    • pp.189-191
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    • 2005
  • In the past, dramatic economical development of Korea could be achieved by well-organized 154kV power system network. Electric power Is a key Industry for the nation and industrial development. Nowadays we operates 345kV Power system with based transmission network and also we are operating 765kV power system to supply to the capital region. Currently developing countries in Southeast Asia are requiring the electric power technology to Korea so that they can acquire the source of the development-power system network. Therefore, it Is important to design transmission line and substation with appropriate methods. In this paper, a calculation and calculating process of shielding range using shield wires in Myanmar 500kV substation are reviewed according to the Myanmar 500kV power system project performed by the overseas projects section of the Korea Electric Power Corporation.

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Development of an Uplift Measurement System for Overhead Contact Wire using High Speed Camera (고속카메라를 이용한 전차선 압상량 검측 시스템 개발)

  • Park, Young;Cho, Yong-Hyeon;Lee, Ki-Won;Kim, Hyung-Jun;Kim, In-Chol
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.10
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    • pp.864-869
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    • 2009
  • The measurement of contact wire uplift in electric railways is one of the most important test parameters to accepting the maximum permitted speed of new electric vehicles and pantographs. The contact wire uplift can be measured over short periods when the pantograph passes monitoring stations. In this paper, a high-speed image measurement system and its image processing method are being developed to evaluate dynamic uplift of overhead contact wires caused by pantograph contact forces of Korea Tilting Train eXpress (TTX) and Korea Train eXpress (KTX). The image measurement system was implemented utilizing a high-speed CMOS (Complementary Metal Oxide Semiconductor) camera and gigabit ethernet LAN. Unlike previous systems, the uplift measurement system using high speed camera is installed on the side of the rail, making maintenance convenient. On-field verification of the uplift measurement system for overhead contact wire using high speed camera was conducted by measuring uplift of the TTX followed by operation speeds at the Honam conventional line and high-speed railway line. The proposed high-speed image measurement system to evaluate dynamic uplift of overhead contact wires shows promising on-field applications for high speed trains such as KTX and TTX.

Technical Feasibility Study on Live-line Maintenance Robot System for Overhead Distribution Lines (가공 배전선로 활선 정비 로봇 시스템의 기술 타당성 검토)

  • Joon-Young, Park;Yoon-Geon, Lee;Young-Sik, Jang
    • KEPCO Journal on Electric Power and Energy
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    • v.8 no.2
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    • pp.49-53
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    • 2022
  • The distribution live-line work method is an operation method of working in a state in which electricity flows through overhead distribution lines to minimize inconvenience to electric customers due to power failure. In June 2016, to strengthen the safety of electrical workers, Korea Electric Power Corporation announced that it would in principle abolish the rubber glove method, in which workers wore protective equipment such as rubber gloves and performed their maintenance work. In addition, KEPCO announced that it would develop a short-range live working method using smart sticks and an advanced live-line maintenance robot system where workers work without touching wires directly. This paper is a preliminary study for the development of the live-line maintenance robot system, and deals with the results of analyzing the technical feasibility of whether the live works performed by workers can be replaced by robots or not.

Analysis of Tensile Strength Characteristics of ACSR due to White Rust (백화현상에 따른 ACSR 송선선로의 인장강도 특성 분석)

  • Park, Dae Keun;Ahn, Jung Hwan;Kwak, Minjun;Jung, Mihee;Choi, Cheol
    • KEPCO Journal on Electric Power and Energy
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    • v.8 no.1
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    • pp.1-4
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    • 2022
  • In this study, a tensile test, one of the mechanical tests, was performed with the collected natural aging ACSR. In order to be used as basic data for predicting the replacement cycle of ACSR, the tensile strength with the normal cables was compared for cables which was caused white rust due to exposure of the hard-drawn aluminum wire surface. Among the ACSR wires collected from various regions, white rust was found on the surface of the small wire, and by checking the tensile strength of them, we would like to suggest the criteria for the ACSR replacement cycle, focusing on changes in mechanical properties.

Optical Current Measuring System for Compensating Interference by Adjacent Electric Wires

  • Cho, Jae-Kyong
    • Journal of Magnetics
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    • v.12 no.4
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    • pp.156-160
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    • 2007
  • In this paper, we analyze the errors associated with magnetic field interference for fiber-optic current sensors working in a three-phase electric system and provide a solution to compensate the interference. For many practical conductor arrangements, the magnetic filed interference may cause errors unacceptable for the accuracy requirements of the sensors. We devised a real time compensation method for the interference by introducing geometric and weight factors. We realized the method using simple electronic circuits and obtained the real time compensated outputs with errors of ${\pm}1%$.

Experimental Study on Tensile Strength of Straight-Line Connection Using Sleeve for Indirect Method (간접활선용 압축 슬리브를 이용한 전선 직선접속에 대한 실험적 연구)

  • Kim, Sang-Bong;Kim, Kang-Sik;Oh, Gi-Dae;Song, Won-Keun;Keum, Ui-Yeon
    • KEPCO Journal on Electric Power and Energy
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    • v.7 no.1
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    • pp.85-91
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    • 2021
  • With the social atmosphere of respect for human life and the increasing interest in safety of field workers, research and development is underway in various ways to transform direct live method into indirect live method in the field of distribution. As part of this measure, it was necessary to convert electric pole and complex facilities work from machining power distribution to indirect live operation, and install a straight connecting sleeve that connects cut wires for by-pass method, but it failed to meet the tensile strength standard when constructing a sleeve constructed by direct method. In this paper, the design factors were derived based on the case of overseas similar sleeves and the tensile strength evaluation of each variable was performed, based on the analysis of these test results, the method for securing tensile strength of straight-line access sleeves for indirect running was presented.

Electrocution caused by a fallen electric wire in Korean native cattles

  • Bae, You-Chan;Lee, Kyung-Hyun;Yoon, Soon-Seek;Heo, Jung-Ho;Lee, O-Soo
    • Korean Journal of Veterinary Research
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    • v.48 no.2
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    • pp.219-221
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    • 2008
  • We report the electrocution of Korean native cattle by a fallen electric wire, which caused the death of thirteen animals. The owner of the cattle felt an electric shock on touching the steel pen and found a fallen 220-V wire on the roof of the barn; additionally, the roof was singed. Clinically, the animals developed spasm, difficulty breathing, and excessive salivation. Histopathologically, many visceral organs revealed severe congestion or hemorrhage, which is consistent with previous reports. This study revealed that the proper installation of electric wires on farms is essential to prevent economic loss by electrocution.

A Study on the Characteristics of Short Circuit through the Cross Section Analysis of Electric Wire (전선의 단면분석을 통한 단락특성에 관한 연구)

  • Shong, Kil-Mok;Choi, Chung-Seog;Kim, Yun-Hoi;Kim, Sang-Hyeon;Park, Nam-Kyu
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2005.05a
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    • pp.51-56
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    • 2005
  • For a fire cause judgement this paper describes the short circuit characteristics of a electric wire through the cross section analysis under ac condition. The cower wires prepared for the experiment were 1.2mm, 1.6mm, and 2.0mm in diameter. Through the cross section analysis(CSA), it was confirmed that the dendrite structure grew at the angle of about $40^{\circ}\;or\;60^{\circ}$ when the fusing current was applied to the wires. The larger the fusing current is, the more decreased the growth angle of the dendrite structure is. It was confirmed that the dendrite structure was arranged like the columnar structure. In this paper, the characteristics analysis of short circuit was carried out in the range of transient duration and the correlation constant k was investigated by measuring the short circuit duration and the fusing current.

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The Heating Characteristics of Electric Bare Wire Melted by AC Current (AC 전류에 의해 용융된 나전선의 발열 특성)

  • Shong, Kil-Mok;Choi, Chung-Seog;Kim, Hyong-Kon;Kim, Young-Seok
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.1
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    • pp.77-84
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    • 2006
  • For a fire cause judgement this paper describes the heating characteristics of electric bare wire melted by AC current. The cower wires prepared for the experiment were 1.2[mm], 1.6[mm], and 2.0[mm] in diameter. Through the cross section analysis(CSA), it was confirmed that the dendrite structure grew at the angle of about 40[$^{\circ}$] or 60[$^{\circ}$] when the fusing current was applied to the wires. The larger the fusing current is, the more decreased the growth angle of the dendrite structure is. It was confirmed that the dendrite structure was arranged like the columnar structure.