• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.251-254
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• 2001

Internal and external forces may be applied on the power cable in the both process of transportation and installation. Even though the EHV power cables have the structure of metal sheath and plastic jacket etc. to minimize these negative influences, the unusual forces result in the unexpected deformation of the cable. Compressing moulded XLPE model cable sheets were prepared and locally dented with round-edge and square-edge tools. All data were analyzed employing Weibull distribution. The breakdown strength of dented molded specimens showed lower values than the normal ones by 10-60%.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.10
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• pp.487-495
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• 2005

This paper reviews the characteristic of thermal and temperature of oil field cable in transient state such as grounding fault and lightning surge. For analysis in various conditions, many actual underground power cable systems are modeled using ATP. These results are applied for the examination of temperature increase when the single line to ground fault by the breakdown of insulation part and hitting of lightning surge are occurred. The inner part temperature of OF cable is analysed according to the various kinds of cable using the thermal model of transient state. The temperature increase of sheath and crossbonded lead bv fault current is also analysed using IEC 60949.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.468-469
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• 2008

In this paper, the effects of earth continuity conductor are deeply analyzed for reducing the level of induced sheath voltage at the single point bonded sections. The various installation conditions of an earth continuity conductor are considered including conductor dimensions, its spacing from the three phase cables, and utilization of two earth continuity conductors when the grounding fault occurs on real power cable systems. Finally, the transient characteristics including reduction effects of induced sheath voltage are proved by EMTP simulations. The optimal installation condition of earth continuity conductor is also proposed based on those results.

• Journal of the Korean Society of Safety
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• v.13 no.3
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• pp.96-101
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• 1998

In order to study the change in mechanical properties and anti-flammablilty of ethylene-ethylacrylate copolymer(EEA) very low density polyethylene(VLDPE) compound that could be used as communication cable sheath using $Mg(OH)_2$ as a non-toxic flame retardant, 100, 125, and 150phr $Mg(OH)_2$ were added to 100 parts of EEA-VLDPE compound, 100 EEA : 0 VLDPE, 50 EEA : 50 VLDPE, and 0 EEA : 100 VLDPE, respectively. $Mg(OH)_2$ was a good non-toxic flame retardant for communication cable sheath and anti-flammability increased with the amount of $Mg(OH)_2$ in compound. The mechanical properties-MI, Ts, and Eb-decreased with increasing in the mixing ratio of EEA but oxygen index(OI) increased with increasing in the amount of EEA. The best composition of $Mg(OH)_2$ in this study was 150phr to 50 EEA : 50 VLDPE compound for the anti-flammability.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.1018-1020
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• 1997

This paper is compared the configuration method of cable cover protection unit with respect to the lightning surge in 154kV underground transmission system. There are many methods of connecting CCPU, i.e, a conventional method, CIGRE method, inter-connection between sheath with grounding, and interconnection between sheath without grounding.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.6
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• pp.857-863
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• 2015

OF cable with excellent reliability and economic efficiency, has been used as the main cable of underground transmission in Korea. However, as XLPE cable is excellent in view points such as reduction of loss, convenience on the construction/operation, and manufacturing technology, it has been replaced as instead of OF cable. Also, when the aging occurs in some sections of OF cable, the section is replaced as XLPE cable without changing of whole cable line. However, there are some differences like electrical constants between both types of cables. Therefore if underground transmission system will be operated as combined connection composited of both cables, it should be proved that overvoltage is stable in steady and transient state. This paper describes the effectiveness of connection operation in combined OF and XLPE cable. For the evaluation of effectiveness, some important analysis such as sheath component voltage, lightning and switching overvoltage, single line-to-ground fault are carried out in steady and transient state. EMTP/ATPDraw is used for modeling and analysis of system.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.8
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• pp.410-417
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• 2005

This paper analyses the transient phenomena against single line to ground fault and lightning surge on underground power cable systems. For analysis in various fault conditions, several actual underground power cable systems are modeled using ATP In ground fault, the transient characteristic of the conductor and the sheath according to the fault current and the installation types of CCPU are analysed. In lightning surge strokes, the various unbalanced conditions including the length of crossbonded lead, the breakdown of CCPU and distance unbalance are considered. This paper is expected to contribute the establishment of proper protection methods against transients on underground power cable systems.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.721-723
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• 2005

This paper analyses the characteristic of temperature and energy of oil field cable in transient state such as lightning surge. For analysis in various conditions, many actual underground power cable systems are modeled using ATP These results are applied for the examination of temperature increase when the hitting of lightning surge are occurred. The inner part temperature of OF cable is analysed according to the various kinds of cable using the thermal model of transient state. The temperature increase of sheath and crossbonded lead by fault current is also analysed using IEC 60949.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.205-207
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• 2003

The line impedance is important data that is applied in all analysis fields of electric power system like power flow, fault current, stability and relay calculation etc. Usually, impedance can be accurately calculated in case of overhead line. However, in case of power cables or combined transmission lines, impedance can not be accurately calculated because cable systems have the sheath, grounding wires, and earth resistance. Therefore, if there is a fault in cable system, these terms will severely be caused much error to calculation of impedance. Therefore, the line impedance were measured for this study in an actual power system of underground cables, and were analyzed by a generalized circuit analysis program EMTP for comparison with the measured value. These analysis result is considered to become foundation of impedance calculation for underground cable.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.621-624
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• 2001

A metal sheath provides a cable with electrostatic screening and a degree of magnetic screening. The presence of a screen on a cable also reduces the induction arising from the high-frequency components of transients caused by power-line switching and also induced transients from lightning strokes; such transient induced voltages are of increasing importance with the increasing use of miniaturized telecommunication equipment with very small thermal capacity. This paper describes electrostatic induction and electromagnetic induction caused by power interference. Also screening factors are proposed.