• Electrical & Electronic Materials
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• v.10 no.9
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• pp.895-900
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• 1997

A Quench in cable-in-conduit (CIC) conductors is often initiated by a disturbance such as strand motion that generates a highly localized normal zone in a strand or a few strands of the CIC conductors. The localized normal zone causes current and heat transfer between a disturbed strand and neighboring strands. Electrical and thermal contact characteristics between strands thus have an effect on the transient stability of the CIC conductors. In this paper the effect of contact characteristics between strands on the CIC conductor stability is presented based on the measured heat transfer characteristics of supercritical helium (SHe) for the local heating. The quench and recovery processes of the strands for the abrupt and highly localized disturbance are analyzed at the boundary between quench and recovery.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.5
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• pp.480-485
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• 2006

A research was undertaken on the thermal properties and behavior of the conductors in a controlled chamber, which was designed to implement the outdoor air temperature, heat and wind conditions With ACSR $410mm^2$ overhead conductors, we measured the maximum temperature of the conductors and the temperature gradient from the core to the surface regions as a function of current, tension, wind velocity and outdoor air temperature. This test also provided a comparative analysis between the measured temperature values of conductors in the controlled chamber and the theoretical calculations of ANSI/IEEE at normal condition. There was not much influence of tension on the conductor temperature. However, the compactness of conductor wires increased with an increase in tension, which eventually increased the coefficient of effective thermal conductivity and, accordingly the conductor temperature was reduced more or less.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.5
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• pp.486-491
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• 2006

A research was undertaken on the thermal properties and behavior of the conductors in a controlled chamber, which was designed to implement the outdoor air temperature, heat and wind conditions. With ACSR $410mm^2$ overhead conductors, we measured the maximum temperature of the conductors and the temperature gradient from the core to the surface regions as a function of current, tension, wind velocity and outdoor air temperature. This test also provided a comparative analysis between the measured temperature values of conductors in the controlled chamber and the theoretical calculations of ANSI/IEEE at normal condition.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.415-420
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• 2003

This paper estimates line constants of equivalent five-conductors model by using the reduced equivalent method. Actually, the catenary system is considered by the equivalent five-conductors model in the electrical aspect. Therefore, we should compose the catenary system of the equivalent five-conductors model. And then we calculate line constants of this equivalent five-conductors model. This paper shows the reducing process about the real system of the field by using the proposed theory and also line constants of reduced system

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.11
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• pp.1042-1048
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• 2008

Forest Fire can cause a serious damage to overhead conductors. Therefore, the detailed investigation for the changes of mechanical and electrical properties of damaged conductors should be carried out to understand the effect of forest fires on conductors. This is very much important to maintain transmission line safely. Especially, this paper describes the changes of mechanical and electrical properties of flame exposed conductor. Overhead conductors temperature were almostly 55$\sim$65% of ambient temperature. Tensile Strength decreased according to incerase of Forest Fire temperature. The detailed will be given in the text.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.274-275
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• 2005

The tensile strain dependency of critical current in YBCO coated conductors was examined at 77K and in the self magnetic field. A commercially available YBCO sample with Cu stabilizer layer was supplied. There existed a peak in the relation between the Ie and tensile strain, and the reversible variation of $I_c$ with applied tensile strain was found. In the neutral axis Ni alloy RABiTS-$Y_2O_3$/YSZ/$CeO_2$ buffered YBCO tape, the $I_c$ recovered reversibly until the applied strain reached to about 0.5%, representing that a significant residual compressive strain induced during cooling to 77 K influenced the axial strain tolerance of YBCO conductors. To investigate the strain and stress influence on the $I_c$, the stress-strain characteristics of YBCO conductors measured at 77 K were discussed.

• Elastomers and Composites
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• v.56 no.3
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• pp.117-123
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• 2021

Electronic skin (or E-skin) is an artificial smart skin composed of one or more than two sensors. E-skins detect external stimuli and convert them into electrical signals. Various types of E-skin sensors exist, including mechanical, physical, and chemical, depending on the detection signals involved. For wearable E-skins with superior sensitivity and reliability, developing conductors that possess both good elasticity and sensitivity is essential. Typical electrical conductors used in these sensors show very high sensitivity, but they have drawbacks such as non-linearity, irreversibility, and a narrow sensing range. To address these issues, stretchable and lightweight ionic conductors have been actively used in E-skin applications. This study summarizes the recent progress on various types of ionic conductors and ionic-conductor-based E-skin sensors.

• The Journal of the Korea Contents Association
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• v.8 no.10
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• pp.309-316
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• 2008

In a study on effect of service education and training for tour conductors upon customer orientation and satisfaction it was shown that in view of insufficient service of education and training for tour conductors and increased number of population travelling by utilizing travel firms and their call for satisfying diverse demand there is need for customer oriented tour conductors to induce customer satisfaction through diverse role playing by tour conductors. It was indicated that such efforts lead to customer satisfaction and also has impact on improving image of company and on creating new customer. In view of such factors there is need for well planned, persistent education and training for service to heighten satisfaction of customer through well organized operation of service education and training program for tour conductors and through its continuous practice and experience.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.3
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• pp.383-389
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• 2016

Kissing of sub-conductors due to magnetic forces has been investigated in a 154 kV bundled overhead transmission line. With increasing ampacity of the conductors and enlarging the distance between spacers, lager magnetic force was measured. When the phase ampacity was 2,000 amps and the distance between two adjacent spacers was 68 m, for instance, the conductors became unstable and vibrated with a frequency of several herts. Furthermore, when the ampacity was 2,250 amps and the distance between spacers was 136 m, the two sub-conductors were contacted. Analysing the magnetic forces with distance of spacers, the safe distance of spacers to avoid contact of sub-conductors was presented. The change of the safe distance is discussed due to various parameters, such as residual stresses and wind pressures, in the real transmission lines.

• Transactions on Electrical and Electronic Materials
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• v.10 no.2
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• pp.66-69
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• 2009

To manufacture YBCO-coated conductors as superconducting fault current limiters, it is important to conduct researches on their durability. To test their durability, it is necessary to investigate their properties before and after the quench in more severe conditions than in general operating conditions. In this study, their voltage-current and resistance properties were measured before and after a fault current was repetitively applied to them. For the applied voltage, the voltage grades of the YBCO coated conductors were considered. The current amplitude was controlled using protective resistance on an experimental track, and the time and number of applications were fixed to produce the quench occurrence at the fault angles of $0^{\circ}$, $45^{\circ}$, and $90^{\circ}$. The operating conditions of the YBCO coated conductors as the main components of superconducting fault current limiters were determined using their voltage properties. The voltage properties of the YBCO coated conductors that were analyzed in this research will be used as important data for their practical application to superconducting fault current limiters.