• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.127-133
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• 2013

As an essential part of current industrial society, electric power energy is contantaly increasing in pace with the development of science and technology. In order to meet the demand of electric power, power facilities which take care of the higher voltage and bigger capacity is required. To produce and supply electric power on a sound basis the electric facilities should operate with reliability. To prevent disasters in advance, the high quality facilities should be manufactured, and a constant management should be done. When the power facilities cause accidents, the result is huge national deficits. Since the power facilities play a pivotal role in the key industry of national infrastructures of they should operate for a long time in maintaining a stable state, and the accidents can be prevented in advance. The lifetime of a power cable is considered to be 30 years at the time of manufacture, but in real fields, accidents of cable occur 8-12 years from the start of operation, resulting in a heavy loss of properties. In this paper, we will show that we have found out the cause and process of the deterioration of 22kV cable systems in operation. The result is that the process of deterioration does not follow the Weibull distribution only ; but rather, after the heat deterioration the Weibull distributed deterioration comes, then the cable is destroyed due to the partial discharge resulting from the Weibull distributed deterioration.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.750-752
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• 2002

An HTS power cable has multi-layer conductor structure to increase the current capacity. However, usually the current is not evenly distributed among the layers. This paper describes a method to make the current distribution more uniform and hence reduce the AC loss. Also. this paper shows recommendation for future cable conductor prototypes.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.822-823
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• 2011

The authors analyzed harmonic current based loss of a high temperature superconducting (HTS) DC model cable. The loss in HTS DC cable is generated due to the variation of magnetic field caused by harmonic current in a HVDC transmission system. The authors designed and fabricated two meters of HTS DC model cable for verification of real loss characteristic. In this paper, the loss characteristics caused by harmonic current in the HTS DC model cable are analyzed using commercial finite element method software package. The loss of the HTS DC cable is much less than the loss of the HTS AC cable but the loss should be considered to decide a proper capacity of cooling system.

• The Journal of the Korea institute of electronic communication sciences
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• v.2 no.1
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• pp.34-39
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• 2007

Submarine cable is the leading means of international communication across oceans. However, when such important submarine cable is damaged, that causes not only huge amount for the repair but also losing the nation's reliability internationally, and has brought about much difficulty and loss due to the interruption of communication. So, in order to deduce methods for the stability of submarine cables, this paper is studying the present status of submarine cables and the causes of cable faults, and suggesting techniques and regulations to protect from the trouble of submarine cables.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.524-526
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• 2005

As a research activity of the project of "Verification Test of Superconducting Power Cable", we measured the AC loss of a short length superconducting power cable. The rating and the length of the cable were 22.9kV, 1,250A and 2.2m. The voltage taps for measuring the AC loss were attached to both ends of the conductor of the superconducting cable. Through the voltage taps and a lock-in amplifier we measured the in-phase component of the voltage($V_x$) with the load current(I). The AC loss was measured by multiplying the in-phase component of the voltage($V_x$) by the load current(I). The value of the AC loss of the superconducting power cable was 1.18W/m/phase/kA at 77.3K, 1atm.

• Progress in Superconductivity
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• v.7 no.1
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• pp.83-86
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• 2005

The High-Tc superconducting power cable consists of a multi-layer high-Tc superconducting cable core and a stabilizer which is used to bypass the current at fault time. Eddy current loss is generated in the stabilizer in normal operating condition and affects the whole system. In this paper, the eddy current losses are analyzed with respect to various structure of stabilizer by using opera-3d. Moreover, optimal conditions of the stabilizer are derived to minimize the eddy current losses from the analyzed results. The obtained results could be applied to the design and manufacture of the high-Tc superconducting power cable system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.5
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• pp.395-402
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• 1991

Submarine Optical Fiber Cable Link becomes a major transmission madi a in many countries and Continents thanks to development of low attenuation fiber and its capability of carryung broadband data. United States of America and Japan are aggressively planning to construct international submarine optical fiber links in North-East Asia. But the links do not connect Korea and Korea becomes isolated in the international communication network. This paper shows a strategy on submarine optical fibre cable links that make Korea a HUB station in North East As a without heavy investment.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.10
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• pp.946-951
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• 2003

A high-Tc superconducting cable(HTS cable) is expected as an underground power line supplying the electrical power the densely populated city in future. The electrical insulation is very important for develop HTS cable system because it is operated a high voltage and in cryogenic temperature. We manufactured a mini-model cable and measured a tan$\delta$ of cable using schering bridge. The tan$\delta$ of PPLP was lower than that of Tyvek and Kraft at a given temperature, the tan$\delta$ of PPLP was 1.16${\times}$10-3. According to the increase of electric stress the tan$\delta$ increased because partial discharge occurred inside butt gap of mini-model cable. However, the tan$\delta$ decreased by increase of liquid nitrogen pressure. This reason is thought by decrease of part discharge between butt gap by increase of liquid nitrogen pressure.

• Progress in Superconductivity and Cryogenics
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• v.1 no.1
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• pp.38-41
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• 1999

Strands composing multistage superconducting cables for AC power applications have twisted structure in each stage for lower AC loss and higher stability. So, when transport currents flow in a cable, each strand is exposed to longitudinal and azimuthal magnetic fields produced by transport current flowing in strand itself and Iongitudinal and transverse magnetic fields by transport current flowing in twisted cable. In this paper. we study the influence on self field lesses generated in second stage superconducting cable for different twist direction of filaments in a strand considering twist of strands in cables.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.1
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• pp.10-14
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• 2001

The superconducting transmission cable is one of interesting part in power application using high temperature superconducting wire. One important parameter in HTS cable design is transport current sharing because it is related with current transmission capacity and loss. In this paper, we calculate self inductances of each layer and mutual inductances between two layers from magnetic field energy, and current sharing of each layer for 4-layer cable using the electric circuit model which contain inductance and resistance (by joint and AC loss). Also, transport current losses which are calculated by monoblock model and Norris equation are compared. As a results, outer layer has always larger transport current than inner layer, and current capacity of each layer is largely influenced by resistance per unit cable length. As a conclusion, for high current uniformity and low AC loss, we have to decrease inductances themselves or those differences.