• Title/Summary/Keyword: 통신케이블

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A study on the Effects of Load Current for Lifetime of Cable Systems (부하 전류가 케이블의 수명에 미치는 영향에 대한 연구)

  • Um, Kee-Hong;Lee, Kwan-Woo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.4
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    • pp.205-209
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    • 2015
  • The economic losses resulted from the accident in the power cables at the power station is not only huge but also requires a great amount of time and expenses to restore to the former condition. In order to prevent these, it is necessary to invent and apply a technique to expect and prevent the accidents. In order to measure insulation resistances of power cables in operation, we derived the relations between load current and temperature. By analyzing data obtained from our measuring equipments, we showed the expected time to change deteriorated cables before accident occurs. We present a result of our study on the effects of the load current on lifetime of 6.6 kV cable systems in operation. With the current flowing through the load of the cable a heat is generated reducing the lifetime of the cable. In order to find out the effect of load current on the lifetime of cable systems, we applied the lifetime theory to the development of two equipments to measure insulation resistance and current of cable systems in operation.

Measurements of Load Current of XLPE Cables Installed at the Load Terminal of Turbine Generator in Operation at Thermoelectric Power Station (화력 발전소의 터빈 발전기 부하단에 설치된 XLPE 케이블의 부하전류 측정)

  • Um, Kee-Hong;Kim, Bo-Kyeong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.17 no.1
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    • pp.207-212
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    • 2017
  • The cables installed to deliver high electric power from a generator at a thermoelectric power station are XLPE (or CV) cables. Depending on the installation and usage conditions, the cables in operation start deteriorating from the time of initial operation. Some cables can cause accidents due to faulty construction or other environmental factors. In order to prevent cable accidents, regular auditing of power cables is required. We have invented a measuring device for systematic surveillance and prevention of accidents, and installed the device at Korean Western Power Co. Ltd. which measures load currents through the cables. In this paper, we present the load current measured using our device, analyze the load characteristics by measures current, compare the ampacity defined by IEC standard, and present a basic data to obtain the temperature of cable conductors.

Comparison and Examination of the Measured Data With the Data from Other Company for the Conductor and Sheath Temperatures of Live 6 kV CV Single Core Cables (활선 6 kV CV 단심 케이블의 도체 및 표면온도 측정 데이터에 관한 타사 데이터와의 비교검토)

  • Um, Kee-Hong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.17 no.3
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    • pp.197-201
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    • 2017
  • The demand for electric power is increasing every year in Korea. All the systems adopted at power stations in order to generate and transmit electric power should operate in perfect condition or reliability. The device for transmitting the generated high-voltage electric power is 6 kV CV single core cables. The manufacturing companies of the cables makes an official announcement that the operating lifetime of their cables is about 30years. But from the moment of operation the deterioration precesses of worsening the characteristics of cables starts. Since the reliability for the status of installed cables in deterioration has not been diagnosed, the cables can be broken at any unexpected moments. In order to prevent the abrupt cable accident by systematically monitoring the cable status, we have invented the first device in Korea. We have installed our device at Korea Western Power Co. Ltd. in order to diagnose the live cables. In this paper, we present our research results of measured temperatures of inner conductor and surface and the compared results of those data with other cable company. We also show that our results agree with those made by other company.

디지털로 무장한 케이블 사용자 확대 '정조준'

  • Park, Hyeon-Su
    • Digital Contents
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    • no.10 s.161
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    • pp.30-34
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    • 2006
  • 급변하는 통ㆍ방 융합 시대를 맞아 케이블방송이 새로운 도전에 직면하고 있다. 그 동안 경쟁매체라고 해봐야 지상파와 위성방송 채널 정도였지만 이제 통신과 방송의 융합이라는 거대 조류 속에서 IPTV, TV포털 등 새로운 개념의 방송 서비스와 경쟁해야만 하기 때문이다. 새로운 경쟁자들이 속속 진입하고 있는 방송 시장에서 과연 케이블방송 업계가 수성에 성공할지 관심이 모아지고 있다.

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Design of Submarine Cable for Capacity Extension of Power Line (전력선 용량증대를 위한 해저케이블 설계)

  • Son, Hong-Chul;Moon, Chae-Joo;Kim, Dong-Sub
    • The Journal of the Korea institute of electronic communication sciences
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    • v.17 no.1
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    • pp.77-84
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    • 2022
  • A submarine power cable is a transmission cable for carrying electric power below the surface of the water. Recently, submarine cables transfer power from offshore renewable energy schemes to shore, e.g. wind, wave and tidal systems, and these cables are either buried in the seabed or lie on the ocean floor, depending on their location. Since these power cables are used in the extreme environments, they are made to withstand in harsh conditions and temperatures, and strong currents. However, undersea conditions are severe enough to cause all sorts of damage to offshore cables, these conditions result in cable faults that disrupt power transmission. In this paper, we explore the design criteria for such cables and the procedures and challenges of installation, and cable transfer splicing system. The specification of submarine cable designed with 3 circuits of 154kV which is composed of the existing single circuit and new double circuits, and power capacity of 100MVA per cable line. The determination of new submarine cable burial depth and cable arrangement method with both existing and new cables are studied. We have calculated the permission values of cable power capacity for underground route, the values show the over 100MW per cable line.

The measuring of induced voltage by the surge current flowing through the shield of telecommunication cable (통신용 케이블 접지를 통해 흐르는 서지 전류에 의한 유기 전압 측정)

  • Park, Shin-Woo;Chae, Sun-Ki;Lim, Byung-Bae
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1187-1188
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    • 2015
  • 접지에 유입된 서지에 의해 각종 통신용 선로나 기기에 미치는 영향을 분석하고 이를 측정하기 위한 시험을 수행하였다. 통신용 케이블 접지에 서지 전류(8/20 us) 또는 링웨이브전류 ($0.5{\mu}s/100kHz$)가 흐를 때 발생되는 유기 전압을 측정하였다. 시험방법은 BNC 케이블의 접지에 서지 전류을 인가하였을 때 BNC 도선과 접지사이의 전압을 오실로스코프를 이용하여 측정하였으며, 시험 결과 서지 전류에 따라 유기 전압은 선형적으로 비례하여 증가되었다. 이를 통해 각종 통신용 보호소자 및 기기에 절연 설계에 참고 자료로 사용할 수 있다.

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Development of System and Measured Results for Measuring Insulation Resistance of High-Power Cables in Operation (활선 고전력 케이블의 절연저항을 측정하기 위한 시스템 설계 및 측정결과)

  • Um, Kee-Hong;Kim, Bo-Kyeong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.4
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    • pp.165-170
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    • 2016
  • The XLPE(or CV) cables installed to deliver high electric power from generator at the power station have operating for the last 40 years in Korea. In 6-8 years from the time of initial operation, the cables in operation start a deteriorating process, depending on the installation and usage conditions. Some cables, even before 6-8 years from the installation, can cause accidents due to the faulty construction or other inadequate environments. In order to prevent cable accident in advance, the regular auditing of power cables are required. For a systematic realization of surveillance and prevention of accidents, we have invented a measuring device. In this paper, we present the device installed at Korean Western Power Co. Ltd., in order to detect the deterioration status of insulation resistances of dielectrics in the cables. We present that the measured results by the device we developed show the deteriorating processes in the cables in operation.

Developing Equipment to Detect the Deterioration Status of 6.6kV Power Cables in Operation at Power Station (발전소에서 운전 중인 활성 6.6kV 전력 케이블의 고장상태를 파악하는 장치의 개발)

  • Um, Kee-Hong;Lee, Kwan-Woo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.4
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    • pp.197-203
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    • 2014
  • The technology to predict and prevent an accident of the cable system in power station is required. The techniques of inactivated diagnosis, partial discharge and $tan{\delta}$, have been adopted to diagnoze the operating characteristics of cables, but it is not so easy to find out problems in cables in an inactive state before the cable accident happens. In this paper, we did a research on the 6.6kV high-power cables, installed at Korean Western Power Station Co., Ltd. in order to diagonize the cables, playing a major role at the station. We have developed an equipment to measure an insulation resistance based on the temperature and current of the cable. By installing the system in a power station, we could find abnormal status for evaluation of the lifetime. In the short term, by analyzing the data, we apply the research result to the diagnosis and evaluation of the 6.6kV power cables. In the long run, however, we plan to reduce the cost of the installation and operation of cable systems at power stations.

홈쇼핑 매체별 소비자 인식 비교

  • 천종숙;양유영
    • Proceedings of the Korean DIstribution Association Conference
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    • 1999.11a
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    • pp.327-338
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    • 1999
  • 본 연구는 카탈로그와 케이블 TV, 인터넷 홈쇼핑 정보전달 매체별로 의류제품에 대한 소비자의 인식 및 기대 수준을 비교 분석하여 홈쇼핑의 정보전달 매체 개발에 기초적인 자료를 구축하기 위하여 설문조사를 실시하였다. 설문조사 대상자는 20세 이상의 카탈로그 홈쇼핑사 회원 219명, 케이블 TV 홈쇼핑사 회원 213명, 네티즌 972명이었다. 매체별 이용자의 분포는 카탈로그와 케이블 TV 홈쇼핑의 경우 여성과 기혼자가 많았고 직업은 주부와 사무직이 많았다. 반면 인터넷 이용자는 남성과 미혼자가 많았고 직업은 사무직이 많았다. 학력은 세 매체 모두 응답자의 절반 이상이 대졸 이상으로 교육수준이 높았다. 설문조사 결과 의류 홈쇼핑에 대한 매체별 소비자의 인식은 다음과 같았다. 1. 케이블 TV 홈쇼핑 이용자들은 케이블 TV를 통해 판매되는 의류제품이 디자인, 색상이 다양하며, 제품의 소재나 품질, 치수에 대한 정보도 충분하다고 느끼며 의류의 품질 신뢰도와 구매의사도 높은 것으로 나타났다. 2. 통신판매를 이용해서 의류를 구매해 본 경험이 있는 집단은 구매를 경험하지 못한 집단보다 구매의사도 높으며 통신판매에 대한 신뢰성도 높은 것으로 나타났다. 특히 케이블 TV 홈쇼핑을 통해 의류제품을 구매해 본 경험이 있는 집단이 의류제품 정보의 다양성에 대한 만족감과 품질 신뢰성이 가장 높았다. 3. 매체와 성별의 차이를 살펴본 결과 케이블 TV를 이용하는 여성은 의류제품의 다양성, 충분한 제품정보, 품질의 신뢰성, 구매의사에 가장 긍정적인 인식을 가지고 있는 것으로 나타났다. 4. 케이블 TV를 이용하는 기혼자와 고소득자가 다른 집단보다 의류제품의 다양성, 제품정보와 품질 신뢰성, 구매의사에서 가장 긍정적인 인식을 가진 집단이었다. 본 연구의 결과는 케이블 TV 홈쇼핑은 카탈로그와 인터넷에 비해 소비자의 욕구를 충족시키는 제품과 소개방식으로 의류를 판매하고 있으며, 특히 의류제품 구매 경험이 있고 고소득층이며 기혼인 여성들을 만족시킬만한 다양한 상품을 구비하고 자세한 제품정보를 제공하며 품질에 대한 신뢰를 심어 주어 긍정적인 구매의사를 갖도록 유도하고 있는 것으로 해석된다.

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Relationship Between Humidity and Insulation Status of XLPE 6.6kV Cables for the Load of Electric Turbine Generator (터빈 발전기 부하용 XLPE 6.6kV 케이블의 절연층 절연상태와 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.185-190
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    • 2016
  • The high-power 6.6 kV XLPE (or CV) cables at Korean electric power stations have been in operation for the last 40 years. Most of the XLPE cables starts deteriorating in 6-8 years from the operating instant of time, some cables may be breakdown at any moment even though they were installed in recent years, causing, huge socioeconomic losses. In order to prevent unexpected cable accident, the operating status of power cables should be monitored in regularly, timely bases. We have invented a device in order to systematically monitor and prevent an abrupt accidents of high-power cables in operation at power station. It has been installed at Korean Western Power Co. Ltd. at Taean, and operating normally for the last 4 years. In this paper, we introduce the functions and operating principles of the measuring device, and present the relationship between humidity and insulation status of XLPE cables for the load of electric turbine generator.