• Title/Summary/Keyword: UHV

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Detemination of Tower Skeleton Diagram for KEPCO 765kV Transmission Lines (765kv 송전용 철탑 Skeleton Diagram 결정)

  • Park, K.H.;Kim, Y.W.;Won, B.J.
    • Proceedings of the KIEE Conference
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    • 1997.07e
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    • pp.1804-1806
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    • 1997
  • Route conditions, applied voltage and the condition of stringing conductors should be considered in determining standard types and skeleton diagrams of towers. In skeleton diagrams the necessary number of insulators and the air clearance have been decided by the results of studies on insulation coordination. Galloping, sleet-jumping, sag characteristics and the possibility of closeness of conductors should be considered according to the condition of stringing conductor and the span. After reviewing those factors, it is necessary to determine the minimum vertical and horizontal distance for the safety of transmission lines under any circumstances. Also it should be economical.

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Insulation design for KEPCO 765kV Transmission Lines (한전 765 kV 송전선로의 절연설계)

  • Koo, B.M.;Won, Y.J.;Hwang, J.I.
    • Proceedings of the KIEE Conference
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    • 1994.07b
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    • pp.1628-1632
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    • 1994
  • KEPCO is now promoting the new project of upgrading its highest system voltage from 345kV to 765kV. The main reason of this project is an insurance of bulk power transmission from power complexes at coast to power demand center at Kyoung-In area. The new system needs a careful approach to basic design to secure its reliability and to reduce the increase of investment cost. So, We introduced the basic philosophy of insulation design in spring meeting of this transaction. This paper, after preceding paper, deals with the insulation design example for 765kV transmission lines.

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DEVELOPMENT OF ELECTRICAL TESTING FACISITY ABOUT U.H.V. CABLE AND ACCESSORY (극 초고압 케이블 및 접속함 전기 시험 단말의 개발)

  • Kim, J.H.;Oh, E.J.;Kim, H.J.
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.2014-2016
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    • 2000
  • In order to meet recent increasing demand for electric power in large cities, plans are being made to introduce 345kV lines into large urban areas. Up to now, OF cables have been used for 345kV fines, but nowadays XLPE insulated cables are preferred as they are easier to maintain due to phenomenal advances in plastic insulation technology, therefore cable manufacturing companies are trying to improve the performance and reliability of UHV CV cables and their accessories. For the purpose, our company has developed facilities for testing UHV cables. In this paper, we describes the methodology adopted for the design and development of a test termination, conducted the electrical test of UHV cables. Based on detailed analytical studies for electrical field distribution, the internal electrical design for the testing end has been carried out.

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Electrical Characteristics of Self-Assembled Organic Thin Films Using Ultra-High Vacuum Scanning Tunneling Microscopy (UHV STM을 이용한 유기 초박막의 전기적 특성 연구)

  • Kim, Seung-Un;Shin, Hoon-Kyu;Kwon, Young-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.108-111
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    • 2003
  • Currently, molecular devices are reported utilizing active self-assembled monolayers containing the nitro group as the active component, which has active redox centers[1]. We confirm the electrical properties of 4,4-di(ethynylphenyl)-2'-nitro-1-benzenethiolate. To deposit the SAM layer onto gold electrode, we transfer the prefabricated Au(111) substrates into a 1mM self-assembly molecules in THF solution. Au(111) substrates were prepared by ion beam sputtering method of gold onto the silicon wafer. As a result, we measured current-voltage curve using ultra high vacuum scanning tunneling microscopy (UHV STM), I-V curve also clearly shows several current peaks between the negative bias region (-0.3958V) and the positive bias region (0.4658V), respectively.

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Development of Reference Impulse Measuring Systems and Investigation on Comparison Tests in Japan

  • Harada, Tatsuya;Kashiwagi, Yasuhide
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.19-23
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    • 1991
  • The revised draft of IEC Publication 60 "High Voltage Test Techniques" introduced a new calibration system for impulse measurements. In order to corespond to this draft, development of reference measuring systems and investigation of comparison tests are being carried out in Japan. This paper is a preliminary report on the topic.

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Live line maintenance technique trend of UHV T/L (초고압 송전선로의 활선공법 기술 동향)

  • Lee, Dong-Il;Choi, In-Hyuk;Jung, Yoon-Hwan
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2005.05a
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    • pp.260-264
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    • 2005
  • This paper gives a basic information of live line maintenance technique of UHV T/L and introduce a technical background and trends of domestic and abroad. The importance of live line maintenance technology getting increased because the change of power system environment and maintenance conditions in korea. this paper explain the present state of the development of live line maintenance technique in korea and show a difference with advanced countries.

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Low-Temperature Si and SiGe Epitaxial Growth by Ultrahigh Vacuum Electron Cyclotron Resonance Chemical Vapor Deposition (UHV-ECRCVD)

  • Hwang, Ki-Hyun;Joo, Sung-Jae;Park, Jin-Won;Euijoon Yoon;Hwang, Seok-Hee;Whang, Ki-Woong;Park, Young-June
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1996.06a
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    • pp.422-448
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    • 1996
  • Low-temperature epitaxial growth of Si and SiGe layers of Si is one of the important processes for the fabrication of the high-speed Si-based heterostructure devices such as heterojunction bipolar transistors. Low-temperature growth ensures the abrupt compositional and doping concentration profiles for future novel devices. Especially in SiGe epitaxy, low-temperature growth is a prerequisite for two-dimensional growth mode for the growth of thin, uniform layers. UHV-ECRCVD is a new growth technique for Si and SiGe epilayers and it is possible to grow epilayers at even lower temperatures than conventional CVD's. SiH and GeH and dopant gases are dissociated by an ECR plasma in an ultrahigh vacuum growth chamber. In situ hydrogen plasma cleaning of the Si native oxide before the epitaxial growth is successfully developed in UHV-ECRCVD. Structural quality of the epilayers are examined by reflection high energy electron diffraction, transmission electron microscopy, Nomarski microscope and atomic force microscope. Device-quality Si and SiGe epilayers are successfully grown at temperatures lower than 600℃ after proper optimization of process parameters such as temperature, total pressure, partial pressures of input gases, plasma power, and substrate dc bias. Dopant incorporation and activation for B in Si and SiGe are studied by secondary ion mass spectrometry and spreading resistance profilometry. Silicon p-n homojunction diodes are fabricated from in situ doped Si layers. I-V characteristics of the diodes shows that the ideality factor is 1.2, implying that the low-temperature silicon epilayers grown by UHV-ECRCVD is truly of device-quality.

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