• Proceedings of the KIEE Conference
• /
• 1995.07c
• /
• pp.1356-1358
• /
• 1995

About 20 years have passed since cross-linked polyethylene(XLPE) came into practical use for power transmission cables. In 1969, We were the first to product 33kV XLPE insulated cables, and in 1984 produced XLPE cable for 154kV. To meet the increasing demand for electric power in large cities, and to improve reliability of the power supply, plans are being made to introduce ultrahigh-tension power cable for long distance underground lines in urban areas. Studies are currently under way to develop more than 154kV XLPE cables to meet increasing demand. In this paper presents the progress in the production and design of XLPE cables, and describes ways in which further improvements seems likely.

• Korean Journal of Veterinary Research
• /
• v.48 no.2
• /
• pp.219-221
• /
• 2008

We report the electrocution of Korean native cattle by a fallen electric wire, which caused the death of thirteen animals. The owner of the cattle felt an electric shock on touching the steel pen and found a fallen 220-V wire on the roof of the barn; additionally, the roof was singed. Clinically, the animals developed spasm, difficulty breathing, and excessive salivation. Histopathologically, many visceral organs revealed severe congestion or hemorrhage, which is consistent with previous reports. This study revealed that the proper installation of electric wires on farms is essential to prevent economic loss by electrocution.

• Proceedings of the KIEE Conference
• /
• 1994.07b
• /
• pp.1553-1555
• /
• 1994

In this paper, we describes the research in condenser cone of $SF_6$ gas sealing end for 345KV oil-filled cable. The designed of condenser cone based on the results electric field analysis by electrostatics theory ana FEM. As a results. we have been designed the condenser cone and the inner insulation part of $SF_6$ seating end, the width and length, the number of condenser, the length of stress relief slope, the total length of condenser cone.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.384-389
• /
• 2011

The electric railway cars are operated by high voltage supply through the catenary wire. Also, numerous electric equipments operated by electric signal are distributed in the electric railway cars. Such electric equipments are exposed to EMI/EMC problems, and there is the possibility that the magnetic field due to the catenary wire current takes effect on the electromagnetic field in the electric railway cars which move under the catenary wire. There is the possibility that the electromagnetic interference generates in view of the operation of many electric equipments in the electric railway cars. There is the possibility that the communication device faults generate, and that the hazards on the human beings generate. In this paper, we predict the magnetic field around the catenary wire, and obtain the exact magnetic field distribution by comparing the analytic results and the numerical results. Finally, we confirmed the possibility of the passive loop mitigation by comparing the analytic results and the numerical results through the passive loop mitigation technique.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.4 no.1
• /
• pp.123-133
• /
• 1996

From the experimental study of wire-cut Electric Discharge Machining of alloyed tool steel and tungsten carbide, the characteristics such as cutting speed, surface roughness has been observed and evaluated for various conditions. Cutting speed is improved as peak discharge current and wire tension become increased, and gap voltage and spark cycle decreased. Surface roughness can be better when peak discharge current and gap voltage become smaller, or spark cycle and wire tension become larger. Secondary cut is recommended to obtain high precision and good quality.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.12
• /
• pp.1711-1716
• /
• 2018

Unlike conventional transmission and distribution lines, catenary system for operating electric railway vehicles are composed of multi-conductor groups (feeder line, contact wire, messenger wire, protection wire) and are used for railway employees, public or passengers in the station yards. Electric shock hazards are exposed and electric shocks such as death or serious injury are occurring in electric railway vehicles, railway high-voltage distribution lines, and catenary system. In order to analyze the types of electric shock accidents on railway by systematic approach method, we modeled 'unsafe behavior classification' method using swiss cheese model. Based on this method, we derived the type of electric shock accidents about railway accidents during the last 5 years by analyzing the frequency of occurrence of human errors and unsafe acts, laws and regulations related to violations, and so on.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.04b
• /
• pp.414-419
• /
• 1995

The wire displacement of wire electric discharge machine has been measured using He-Ne laser. A measurement system consisted of He-Ne laser, A/D converter, 4 divided photodiode, amplifier, sensor process instrument, and personal computer. The processing parameters were varid with feed rate, wire tension, wire speed and voltage. The laser beam intensity transmitted on a 4 divided photodiode was varied by processing wire electric descharge machine with various process parameters. The 4 divided photodiode and amplifier were used to change the detected beam intensity into voltage. Variation of wire displacement was between 11 and 125 .mu. m. The wire tension was dominant on the variation of wire displacement among many parameters.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.10
• /
• pp.3756-3760
• /
• 2010

In this paper we propose network design for power line communication of electric railway using messenger wire. we carried out feasibility study on the power line communication(PLC) using Contact wire and messenger wire which are required at electric railway. First of all, full-duplex data communication was implemented using coupler which is suspended on messenger wire at non-voltage state. We verified data transfer rate was found to be good, and then proposed a design example of PLC network as the main components for PLC. we will study continuously make an effort to verify on the network design of PLC for further study.

• Journal of the Korean Society of Safety
• /
• v.17 no.1
• /
• pp.11-17
• /
• 2002

The purpose of this study was to present the method to choose the optimization machining condition for the wire electric machine. This was completed by examining the ever-changing quality of the material and by improving the function of the wire electric discharge machine. Precision metal mold products and the unmanned wire electric discharge machining system were used and then applied in industrial fields. This experiment uses the wire electric discharge machine with brass wire electrode of 0.25mm. To measure the precision of the machining surface, average values are obtained from 3 samples of measures of center-line average roughness by using a third dimension gauge and a stylus surface roughness gauge. In this experiment, we changed no-node voltage to 7 and 9, pulse-on-time to $6{\mu}s,\;8{\mu}s$ and $10{\mu}s$, pulse-off-time to $8{\mu}s,\;10{\mu}s$ and $13{\mu}s$, and experimented on wire tension at room temperature by 1000gf, 1200gf, and 1400gf, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.260-260
• /
• 2010

In recent years, polymer/clay nanocomposites have generated a great interest, both in industry and in academia, because they often exhibit remarkable improvement in material properties when compared with the virgin polymer or conventional micro and macro-composites. Among these properties are stiffness, strength, dimensional stability and permeability. [1-3] The dispersion of hydrophilic silicates in a hydrophobic matrix like Polyethylene (PE) is difficult because of the difference in character between PE and Montmorillonite (MMT). Therefore, it is necessary to modify PE with polar groups, which can increase the hydrophilicity of PE. In this study, High density polyethylene (HDPE)/$Mg(OH)_2$/Montmorillonite (MMT) nanocomposites having a various compositions were prepared by a melt blending technique with an internal mixer and properties namely mechanical, morpology, rheological and thermal properties were investigated