• Journal of the Society of Disaster Information
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• v.11 no.1
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• pp.135-147
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• 2015

Recent underground common utility tunnels are underground facilities for jointly accommodating more than 2 kinds of air-conditioning and heating facilities, vacuum dust collector, information processing cables as well as electricity, telecommunications, waterworks, city gas, sewerage system required when citizens live their daily lives and facilities responsible for the central function of the country but it is difficult to cope with fire accidents quickly and hard to enter into common utility tunnels to extinguish a fire due to toxic gases and smoke generated when various cables are burnt. Thus, in the event of a fire, not only the nerve center of the country is paralyzed such as significant property damage and loss of communication etc. but citizen inconveniences are caused. Therefore, noticing that most fires break out by a short circuit due to electrical works and degradation contact due to combustible cables as the main causes of fires in domestic and foreign common utility tunnels fire cases that have occurred so far, the purpose of this paper is to scientifically analyze the behavior of a fire by producing the model of actual common utility tunnels and reproducing the fire. A fire experiment was conducted in a state that line type fixed temperature detector, fire door, connection deluge set and ventilation equipment are installed in underground common utility tunnels and transmission power distribution cables are coated with fire proof paints in a certain section and heating pipes are fire proof covered. As a result, in the case of Type II, the maximum temperature was measured as $932^{\circ}C$ and line type fixed temperature detector displayed the fire location exactly in the receiver at a constant temperature. And transmission power distribution cables painted with fire proof paints in a certain section, the case of Type III, were found not to be fire resistant and fire proof covered heating pipes to be fire resistant for about 30 minutes. Also, fire simulation was carried out by entering fire load during a real fire test and as a result, the maximum temperature is $943^{\circ}C$, almost identical with $932^{\circ}C$ during a real fire test. Therefore, it is considered that fire behaviour can be predicted by conducting fire simulation only with common utility tunnels fire load and result values of heat release rate, height of the smoke layer, concentration of O2, CO, CO2 etc. obtained by simulation are determined to be applied as the values during a real fire experiment. In the future, it is expected that more reliable information on domestic underground common utility tunnels fire accidents can be provided and it will contribute to construction and maintenance repair effectively and systematically by analyzing and accumulating experimental data on domestic underground common utility tunnels fire accidents built in this study and fire cases continuously every year and complementing laws and regulations and administration manuals etc.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.363_364
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• 2009

Even though underground transmission cable is an essential transmission method to supply stable power for downtown and population center, interaction of electromagnetic force from fault current is very large comparing to overhead transmission line due to restricted installation space such as tunnel, etc. and close consideration is required for it. This paper presents countermeasures to reduce and release the effect of electromagnetic force with rope binding and installation of spacer and describes its efficacy through three phase short-circuit test, which will be utilized as basic materials for improvement and development of cleat, hanger, etc. to reduce and release effect of electromagnetic force in the future.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2268-2270
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• 1999

The underground transmission line have been consistently developed to increase its voltage level for satisfying the customer's demand through supplying the high reliability power. The underground XLPE cable and its accessories of 500kV level have been already developed internationally, but the XLPE cable have been installed 154kV level in Korea up to now. Thus, our company has developed 230kV XLPE cable and its accessory in 1998 for preparing 345kV level system in Korea and being qualified as international cable maker of developing oversea markets. In this paper, newly our developed 230kV system will be introduced using the type test result according to IEC 840 and additional specification.

• 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.

• Journal of Environmental Impact Assessment
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• v.23 no.5
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• pp.353-363
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• 2014

The purpose of this study was to investigated the ELF-MF emission level of various environments such as 258 facilities near located to high voltage transmission lines and 120 high voltage transmission lines, 17 underground cable lines. In addition, ELF-MF reduction rate according to separation distance was calculated by using simulations. An appropriate separation distance showing below 4mG was at least 70m. In the case of the appropriate separation distance for 120 high voltage transmission lines, 154kV required 20m of separation distance and 345kV required 60m of separation distance. The simulation results showed that the appropriate separation distance showing below 4mG was 40m and 60m for overhead 154kV and 345kV respectively. To adjust the worst conditions considering the aspects of environmental impact assessment study and the electric power currents that will increase in the future, the appropriate minimum separation distance for HVTL is judged to be above 70m in this study. Thus, there is a need to establish the greenbelt or buffer zone within 70m so as to create an environment in which the receptors are not exposed and thereby eliminate the risk factors of ELF-MF against humans.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2093_2094
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• 2009

오늘날 국내 지중선로는 주로 XLPE케이블과 OF케이블로 구성된다. 기존 사용되던 OF케이블의 화재 위험성 및 환경오염 문제 등으로 인해 XLPE케이블의 비중이 점차 높아지고 있지만 XLPE케이블의 경우 운전 중 케이블의 열화나 절연진단 등이 쉽지 않은 점이 문제로 제기되고 있다. 그나마 XLPE케이블에 대한 PD측정은 현재로서는 가장 유용한 케이블 진단기법으로 알려져 있으며 그 활용성과 신뢰성을 높이기 위한 연구가 국내외적으로 계속되고 있는 실정이다. 본 논문에서는 실제 운전 중인 154kV 지중송전선로에 대해 PD측정을 수행하고 그 결과로 취득된 Pattern의 분석을 통해 선로내부에서 PD가 발생하고 있는지 판별하는 과정을 소개하였다.

• Proceedings of the KIEE Conference
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• 2008.10a
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• pp.87-88
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• 2008

지중송전선로는 가공송전선로와는 달리 고장발생시 영구고장이 대부분이며 따라서 고장복구 기간도 상대적으로 긴편이다. 고장 후 신속한 복구를 위해서는 무엇보다 고장원인을 빠르고 정확히 밝혀내는 것이 중요하다. 본 논문에서는 우리회사가 시행하고 있는 XLPE케이블 고장분석 종류와 그 결과를 통한 고장원인 도출까지의 과정을 다루었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.112-112
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• 2010

The purpose of development is to localize a connector for connection of cable and GIS for underground transmission system. The cable connector for GIS provides electrical insulation of GIS housing part and makes connection of ultra high voltage electrical apparatus and power cable by controlling electrical stress between electrodes of power cable termination. Generally Korean switchgear makers are using a connector for GIS made by foreign companies. We manufactured sample by best structure design of great capacity conductor connecting part and then modified the design by analysis of shape and section. We completed the suitable sample for current cycling test condition of conductor connecting part sample and ensured surge characteristics of line by short-time current test.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.111-111
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• 2010

The mold transformers have been widely used in underground substations in large building and have some advantages in comparison to oil-transformer, that is low fire risk, excellent environmental compatibility, compact size and high reliability. In addition, the application of mold transformer for outdoor is possible due to development of epoxy resin. The mold transformer generally has cooling duct between low voltage coil and high voltage coil. A mold transformer made by one body molding method has been developed for small size and low loss, but it needs some cooling method because heat radiation between each winding is difficult. In this paper, the temperature distribution and thermal stress analysis of H class 100kVA pole cast resin transformer for power distribution are investigated by FEM program.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.158-160
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• 1997

WHEN IT IS REQUIRED TO CONNECT OVERHEAD TRANSMISSION LINE WITH UNDERGROUND CABLE, PREVALENT METHOD WAS TO USE CABLE HEAD TYPICALLY MADE OF LATTICE STEEL STRUCTURE. BUT IN VIEW OF THE INCREASING DEMAND THAT STEEL STRUCTURE INSTALLED IN URBAN AREA AND/OR RESIDENTIAL AREA NEED TO MATCH WITH ENVIRONMENTAL SURROUNDINGS, THE UNSHAPELY LARGE-SIZED LATTICE STEEL STRUCTURE CAN NOT BE A PROPER ONE BECAUSE THAT IT IS NOT WELCOMED BY THE RESIDENTS AND ACCORDINGLY ITS INSTALLATION TENDS TO CONFRONT WITH CIVIL PETITION. AS AN ALTERNATIVE METHOD TO SETTLE AFOREMENTIONED UNFAVOURABLE SITUATION WE MAY BE UNDER, WE AR INTENDING TO DEVELOP THE CABLE HEAD MADE OF TAPERED TUBULAR STEEL POLE AND TO PUT IT TO PRACTICAL USE. THE ADVANTAGE WE CAN TAKE OF THE TAPERED TUBULAR STEEL POLE IS THAT IT CAN BE INSTALLED IN A VERY LIMITED SPACE MAXIMIZING THE UTILITY VALUE OF THE LAND AND THAT ITS SMART SHAPE WITH COLOUR COATING IN CONSIDERATION OF AESTHETIC AESTHETIC CAN BE IN GOOD HARMONY WITH THE SURROUNDINGS.