• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.3
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• pp.196-201
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• 2000

It is very important not only to detect PD signal but also to locate PD source in power cable line including its accessories. In this paper, the PID localization technique using interruption of metal sheath of cable or accessory is described. By interruption of metal sheath, the polarity of PD pulse to be measured on each part can be compared. With this technique, the exact location of PD in the accessory which has some defects can be found. Although the 'Soft' interruption method, that is, cable sheath is divided by semi-conductive layer with the resistance of higher than 1 k$\Omega$, was used instead of 'Hard' interruption method, it is also possible to detect exact location of PD. This technique is considered to be very effective for detecting PD localization in the type test of cable and accessories.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.1
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• pp.19-25
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• 2000

This paper describes the sheath induced voltage in underground transmission cable system which will be operated with cable cover protection unit(CCPU). Simulation was carried out to analyze the sheath induced voltage in the real cable system which was installed by 154㎸ CV cable in the case with and without CCPU. The sheath induced voltage will be also analyzed according to the change of grounding method, fault resistance and fault angle. Simulation was performed using EMTP and ATP Draw, the simulation results show whether the CCPU in necessary or not in underground transmission power cable system.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.175-177
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• 2002

The use of underground transmission cables has increased continuously in densely inhabited urban and suburban for power transmission. Two or more transmission lines are outgoing from one substation in many cases, and one line comprises twin circuits. In order to meet the increasing do and for electric power, underground tables of two or fore circuits are installed in ducts in parallel for several kilometer in the same route. It, however, has not been known generally that the sheath circulating current is generated in a system where a large number of cables are laid on the same route. Therefore, this paper describes an improved analysis method for sheath circulating current on underground transmission cables using EMTP. Author propose several methods to reduce sheath circulating current. The analysing method and reduction methods for two or more underground cables will be really improved for cable system utility.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1354-1356
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• 1994

In order to protect cable from rat's biting, a development of rodent repellent is described. This cable has double coated sheath such as construction of skin layer over the conventional cable sheath. Stabilized rodent repellent agent which has good compatibility with PVC is employed in a skin layer. Rodent repellent layer has highly residual properties of agent through the manufacturing process, and meets the general requirements of cable sheath. Also, rat repellent effect is excellent.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.7
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• pp.421-428
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• 2003

After the cable is installed, many geometric factors, such as bowing types of the cable and the length difference of the cable between each minor section will cause the impedance unbalance between cables. The impedance unbalance will increase or decrease the sheath circulating currents, which are critical to human safety and sustaining the capabilities of electric power. Accordingly, in this paper, a new method is also proposed to reduce the sheath circulating currents and an reduction equipment according to the theory of the new method is developed. The reduction equipment is tested when the cable is on service. The test results show that it can reduce the sheath circulating currents by up to 97.8［%］. This confirms the validation of the new method and the reduction equipment, and assures the safe operation of the transmission cables. In order to illustrate the safe operation of the cable with new current reduction equipment at transient state due to lightning and single line-to-ground fault, extensive simulations have been made. Then the protection scheme of sheath circulating currents reduction equipment is proposed by adopting the new device of RDP(Reduction Device Protector).

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1179-1181
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• 1998

This paper describes the induced voltage of sheath on 154kV transmission power cable in multi fault states. Simulation was carried out to obtain the induced voltage of sheath according to change of, fault angle and grounding resistance using EMTP. Modeling of cable system is also established in EMTP to analyze. The simulation results can be useful reference to design cable system in power system.

• Special Issue of the Society of Naval Architects of Korea
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• 2009.09a
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• pp.18-23
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• 2009

After the installation of electric cables at block, PE(pre-erection) and hull stages, the coating stains on the electric cable sheath were unavoidably occurred by additional painting process. According to class rules paint or coating applied on the electric cables shall not adversely affect the mechanical, chemical of fire resistant characteristics of the electric cable sheath. However, there has not been quantitatively studied about the effect of coating stains on properties of sheath materials. In this study, we tried to investigate the effect of coating stains on the performance and deterioration of sheath materials by using FTIR, SEM analysis, flame retardant, high potential voltage and tensile test. The results sowed that coating stains, which were occurred during painting work on site could not adversely affect on the performance and deterioration of sheath materials.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.4
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• pp.389-392
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• 2020

In order to accurately predict the losses in the power cable, analysis of the eddy current losses in the metal sheath is required. The copper loss is easily calculated by the resistance and current of the conductor, but it is difficult to measure and predict the eddy current generated from the metal sheath. For this purpose, the previous study analyzed the eddy current loss in single phase cable, but there is a limit to apply it because three phase cables are used in real environment. Therefore, in this paper, the eddy current loss occurring in the metal sheath of three phase cable according to the cause was analyzed theoretically. In addition, the eddy current loss occurring in the triangular and horizontal array were predicted through electromagnetic numerical analysis.

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.405-407
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• 2006

The power system analysis based on the accurate impedance of the individual underground cable, which is the inter connected to a large power system, is required. A study on calculation method of impedance allowable current for underground cables. furthermore, various methods of bonding and earthing the sheath have been used for the purpose of eliminating or reducing the sheath losses. the effectes of bonding and earthing must be includied in impedances. therefore, the subject of predicting thermal performance of soil and cable systems has been received increasing attension. for these problems, this paper describes a general formulation of impedance that is based on the effect of crossbonding and earthing of the sheath on the 66kV, 132kV and 220kV underground cable systems. also the work is presented, for calculating the temperature rise of power cable and soil.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1391-1393
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• 1999

This paper have analyzed sheath induced voltage in underground transmission cable system which will be operated with cable cover protection unit(CCPU). Simulation was carried out to analyze sheath induced voltage using on real cable system in the case with and without CCPU. Sheath induced voltage was also analyzed according to grounding method, fault resistance and fault angle. Simulation was performed using EMTP and ATP Draw, the simulation results represent whether the arrester is necessary or not in cable system.