• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.143-146
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• 1987

Fiber optics provide a solution to the problems at interference, capacity and reliability in communication. Approximately 20 kilometera of a six-fiber, multimode, longwave($1.3{\mu}m$), graded index silica glass fiber optic cable was helically wrapped around a phase conductor at a Korea Electric Power Corporation(KEPCO) 154KV transmission line. This paper presents an economic comparison of several fiber optic cable installation alternative and discusses the characteristics at the helically wrapped fiber cable, as well as the entire installation, including high voltage phase-to-ground (PTG) end termination, and splicing. The fiber link was installed for the field trial and practical use with overhead composite optical fiber cable which installation performed a few years earlier some other location and is intended to accommodate not only telephone but also supervisory Control and Data Acquisition(SCADA), protective relaying, and telemetry functions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.4
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• pp.554-560
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• 2018

Since Korea has a small land area, it is expected to construct the conductor return type with neutral wire in the case of ${\pm}500kV$ HVDC double bipole transmission line. Therefore, in order to apply ${\pm}500kV$ HVDC double bipole transmission line with neutral wire in Korea, it is necessary to develop technology for insulation and environmental designs. In this study, radio interference, audible noise, electric field and ion current density according to the polarity arrangement were compared and assessed in the ${\pm}500kV$ HVDC double bipole transmission line with the conductor return method. And the optimum configuration of HVDC double bipole transmission line was determined from the viewpoint of electrical environment.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.9
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• pp.730-735
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• 2010

Forest fire can cause a serious damage to overhead conductors. Therefore, detailed investigation on 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 of critical importance in maintaining transmission line safely. This paper examines the changes of mechanical and electrical properties of flame exposed conductor. Tensile strength (TS) decreased according to increase of forest fire temperature and conductivity changed according to forest fire temperature. Specimens were aluminum conductors of aluminium conductor steel reinforced (ACSR) 410, 240, 480 $mm^2$. In this paper, the electrical and mechanical characteristics of forest fires exposed overhead conductors depending on the diameter of aluminum conductors are presented. It was possible to estimate the degree of deterioration caused by forest fires. The detailed results are given in the paper.

• Progress in Superconductivity and Cryogenics
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• v.2 no.1
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• pp.19-23
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• 2000

We are developing a small-sized superconducting magnetic energy storge ($\mu$SMES) magnet with the storage capacity of a few megajoules, which provides electric power with high quality to sensitive electric loads. A kA class superconductor with a high coppe $r^erconductor ratio was selected as a candidate conductor. The superconductor was tested in two points of view, which are basic and important in development of the $\mu$SMES magnet. First, stabilities of the superconductor against localized disturbances such as wire motions were estimated by using a wire heater. Second, the quench current characteristics for different charge rates were also tested. The stability data showed that the short heat pulses made the conductor more unstable. The superconductor had relatively high recovery currents ranging between 40% and 50% of its critical currents. The quench tests indicated that the quench currents of the conductor were independent of current ramp rates up to 3000 A/s and nearly equal to its cuitical current data.ta.

• Current Photovoltaic Research
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• v.3 no.4
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• pp.116-120
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• 2015

A hybrid transparent conducting layer was applied for Si photodetector. To realize the hybrid transparent conducting layer, a 200 nm-thick ITO layer was deposited onto a Si substrate, following by a solution-processed AgNWs-coating on the ITO. The hybrid transparent conducting layer showed an excellent low electric resistance of $15.9{\Box}/{\Omega}$ with a high optical transparency of 86.89%. Due to these optical and electrical benefits, the hybrid transparent conductor-embedding Si diode provides an extremely high rectifying ratio of 3386. Under light-illumination, the hybrid transparent conductor device provides extremely high photoresponses for broad wavelengths. This implies that a functional design for hybrid transparent conductor is crucial for photoelectric devices and applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.521-522
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• 2007

A new high strength conductor was designed for long span transmission line with a high nitrogen steel having high tensile strength and non-magnetic properties and high strength AI alloy. The tensile strength of conductor is very important to reduce the sag. The height of electric tower depend on the sag also. More than 36% less of sag was achieved by using ACHR(Aluminum conductor stranded high-nitrogen steel reinforced) instead of conventional ACSR.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.2
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• pp.173-180
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• 2003

Effects of the electric conductivity of particles were studied for the aggregation process of charged particles with a Brownian dynamic simulation in the free molecular regime. A periodic boundary condition was used for the calculation of the aggregation process in each cell with 500 primary particles of 16 nm in diameter. We considered two extreme cases, a perfect conductor and a perfect nonconductor. The electrostatic force on a particle in the simulation cell was considered as a sum of electrostatic forces from other particles in the original cell and its replicate cells. We assumed that aggregates were only charged with pre-charged primary particles. The morphological shape of aggregates was described in terms of the fractal dimension. The fractal dimension for the uncharged aggregate was D$_{f}$= 1.761. However, the fractal dimension decreased from 1.694 to 1.360 for the case of the perfect conductor, and from 1.610 to 1.476 for the case of the perfect nonconductor, with the increase of the average number of charges on the primary particle from 0.2 to 0.3. These values were smaller than that of the centered charge case.e.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.1
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• pp.79-84
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• 2008

We are developing a small-sized high temperature superconducting magnetic energy storage (HTS-SMES) magnet with the nominal storage capacity of 600 kJ, which provides electric power with high quality to sensitive electric loads. Critical current and N-value of a high temperature superconductor with large current, which was selected for the development of the 600 kJ HTS-SMES magnet, were investigated in various oblique external magnetic fields. Based on the critical current and N-value measured for the short sample conductor, we discussed the DC V - I characteristic of a model coil fabricated with the same conductor of 500 m. The results show that the measured critical current and N-value of the conductor for parallel field are constant in external magnetic fields less than about 0.2 T. However, for oblique fields, its critical current and N -value abruptly decrease in all external magnetic fields. Moreover, the measured critical current of the model coil well agrees with the numerically calculated one based on the DC V - I characteristic measured for the short sample conductor. This suggest that losses and critical currents for an HTS-SMES magnet made up of a high temperature superconductor with anisotropic characteristic are predictable from the data of a short sample conductor.

• Progress in Superconductivity and Cryogenics
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• v.24 no.4
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• pp.40-45
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• 2022

The electrical/thermal stabilities and magnetic field controllability of a no-insulation (NI) high-temperature superconducting magnet are characterized by contact resistance between turn-to-turn layers, and the contact resistance characteristics are determined by properties of conductor surface and winding tension. In order to accurately predict the electromagnetic characteristics of the NI coil in a design stage, it is necessary to control the contact resistance characteristics within the design target parameters. In this paper, the contact resistance and critical current characteristics of a rare-earth barium copper oxide (REBCO) conductor were measured to analyze the effects of surface treatment conditions (roughness and oxidation level) of the copper stabilizer layer in REBCO conductor. The test samples with different surface roughness and oxidation levels were fabricated and conductor surface analysis was performed using scanning electron microscope, alpha step surface profiler and energy dispersive X-ray spectroscopy. Moreover, the contact resistance and critical current characteristics of the samples were measured using the four-terminal method in a liquid nitrogen impregnated cooling environment. Compared with as-received REBCO conductor sample, the contact resistance values of the REBCO conductors, which were post-treated by the scratch and oxidation of the surface of the copper stabilizer layer, tended to increase, and the critical current values were decreased under certain roughness and oxidation conditions.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1775-1777
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• 2004

Taihan Electric Wire Co. developed accessories(PJ, EB-G, EB-A, EB-O) for 345kV XLPE $1C{\times}600mm^2$ cable as a small size conductor cable, after installed 345kV XLPE $1C{\times}600mm^2$ cable, PJ and EB-G on Youngseo${\sim}$Youngdeungpo project KEPCO planed in 2003. All of 345kV XLPE $1C{\times}600mm^2$ cable Accessories are finished the type tests successfully. Straight joint as a Prefabricated Joint(PJ) had shorter the days of assembling than those of TMJ used on the 154kV XLPE Cable. Particularly, the use of clean booth to prevent the dusts and the penetration of water also had made the quality of jointing improved.