• Title/Summary/Keyword: 통신케이블

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Design of Measuring System for Insulation Resistance and Humidity in High-Power XLPE Cables in Operation and the Relationship Between Insulation Resistance and Humidity in the Oversheath (운전 중인 고전력 XLPE 케이블의 절연저항과 습도의 측정 시스템 설계 및 방식층 절연저항과 습도의 상관관계)

  • Um, Kee-Hong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.5
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    • pp.179-184
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    • 2016
  • The usual way used by electric power stations to deliver high levels of generated power is via 6.6kV XLPE (or CV) cables. Depending on the manufacturing technique, installation environment, and usage conditions, the deterioration processes of the power cables start from the instant of operation. Cable junctions may break down in three years from the start of operation due to the manufacturing or construction defects. Otherwise they should be in good working order for 20-30 years. When the cable system (the cable itself and cable junctions combined) deteriorates, fire accidents happen due to the dielectric breakdowns. We have invented a device to monitor the deteriorating status of cables at Korean Western Power Co. Ltd. located in Taean, Chungcheongnam-do province. In this paper, we introduce the device hardware. Using the device, we have measured the insulation resistance and humidity in the sheath of the cables. We present, in analysed results, the effect of humidity on insulation resistance in cable sheaths.

Screening Effects of Double-track Electric Railway and Shielded Cables on Communication-Line Inductive Interference (전기철도 복선화 및 차폐 케이블 적용에 따른 통신선 유도장해 차폐 효과)

  • Seol, Il-Hwan;Choi, Kyu-Hyoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.10
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    • pp.5148-5155
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    • 2013
  • The induced voltage on the telecommunication cable generated by nearby electric railway system may bring about telecommunication errors and safety accidents. In order to reduce the induced voltage and to achieve communication reliability, the effect of the shield cables and the recent double-track railway systems on the inductive interference should be investigated. This paper analyzes the parameters which seriously influence the induced voltage on the telecommunication cables which run parallel with a AT-fed electric railway line, and provides a simulation-based approach to estimate the amount of the induced voltage. Simulation results indicate that the induced noise voltage generated by a double-track railway decreases by 18 % compared to that generated by a single-track railway, showing the screening effect by nearby track. The induced noise voltages on the 50%-shielded cable and 15%-shielded cable decrease to 1/8 and 1/15 of the induced voltage on the non-shielded cable, respectively. A meaningful shield effect is achieved and the induced voltage is minimized by the double-track railway and the shielded cable.

디지털 케이블TV기술 및 향후 전망

  • Han, Un-Yeong
    • The Magazine of the IEIE
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    • v.35 no.9
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    • pp.58-69
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    • 2008
  • 디지털 케이블TV서비스는 헤드엔드(Head-End)센터로부터 QoS (Quality of Service)가 보장되는 케이블 HFC(Hybrid FiberCable)망을 통해 디지털 영상 방송이나 양방향서비스를 가입자 단말까지 제공하는 방송 통신 융합서비스이다. 본 고에서는 디지털 케이블TV 서비스를 제공하기 위한 디지털 케이블 네트워크 기술에 대해서 설명하고, 디지털 방송 및 양방향 서비스를 송출하는 방송센터시스템과 디지털 방송 기술에 대해 알아본 후 마지막으로 디지털 케이블TV의 향후 전망에 대해서 살펴보기로 한다.

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Serial interface system of HDTV signal in coaxial cable (동축케이블을 이용한 HDTV 신호의 serial 전송 방식)

  • 이호웅;이문기;강철호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.3
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    • pp.622-628
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    • 1996
  • This paper describes a new serial interface system which uses conventional 75 ohm coaxial cable. Typically parallel 25 pin cable and connectors are used to transfer and receive the data between digital systems such as HDVCR, D3 VTR and HDTV Receiver. The coaxial cable is more desirable for consumer product applications and also for studio applications where long signal paths and switching are required. This serial data transfer technique is thoroughly tested and utilied in the data transmission/reception between systems more than 200 feet apart. It is also cost effective because it does not require RF PLL, SCRAMBLING, and NRZI hardware.

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Identification of Normally Operating High-Voltage Cables beyond Expected Life time (예상 수명을 초과하여 정상적으로 동작하는 고압 케이블의 확인)

  • Um, Kee-Hong;Lee, Kwan-Woo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.5
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    • pp.207-212
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    • 2015
  • Continuous, high-quality supply of electrical energy is the backbone of any modern economy. Any equipment operating at a power station must be reliable and safe. All major power supply components such as transformers, cables, generators, and switchgear need to be kept in perfect operating condition. The lifetime of power cables, used as the main means of transferring electric power, is understood to be about 30 years, from the time of manufacturing. The dielectrics between two conductors of a cable must be able to withstand electrical stresses from high-voltage input. This condition should be verified throughout the lifetime of the cable system. Several techniques, such as VLF-tan${\delta}$, partial discharge, and insulation resistance are used in order to determine the operating conditions of cables. In this paper, we present our work on insulation resistance to diagnose cables in operation at the Western Power station in Taean, Chungcheong Namdo Province, South Korea. As a result we have found cables the life time of which is 38 years.

The cases of applying submarine optical fiber cable to control HVDC link between JEJU and main land (육지-제주간 초고압직류연계선로 제어용 해저광통신케이블 도입사례)

  • Yoo, Sung-Hwan;Yoo, Dong-Hee;Hong, Seung-Taek;Shin, Hyun-Jo;Joo, Jae-Seong
    • Proceedings of the KIEE Conference
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    • 2008.11a
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    • pp.400-402
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    • 2008
  • 제주도의 지속적인 전력수요 증가에 능동적으로 대처하고자 육지-제주간 초고압 직류연계(HVDC) 추가 건설사업이 추진 중에 있다. 초고압 직류 송전계통을 신뢰성 있게 운전하기 위해 양측 변환소에 설치될 제어 및 감시계통간 정보전송로의 화보는 매우 중요하다. 본 논문에서는 고품질, 대용량화 되어가는 전력데이터를 안정적으로 전송하고 해저케이블 고장감시 및 향후 정보 통신 분야의 부가가치 창출을 위한 최적의 해저광통신케이블을 소개하고자 한다.

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