• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2332-2334
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• 1999

This paper presents the results of multi-stress chamber experiments done to examine the tracking and erosion performance of polymer insulator. Multi-stress testing is able to demonstrate deficiencies of polymer insulator materials and designs including the nature of interfaces in insulation design. Therefore, multi-stress testing is believed to a suitable test for evaluating the aging performance of polymer insulator designs. We have investigated IEC 61109 Annex C for estimating long time performance of polymer insulator.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.11
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• pp.66-75
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• 2007

To prevent an insulator failure, an automatic cleaning and inspection robot was developed for suspension insulator strings. The robot autonomously moves along the insulator string using the clamps installed on its two moving frames. Especially, unlike the existing cleaning robots using jets of water, the robot system adopts a dry cleaning method using rotating brushes and a circular motion guide. In addition, a mechanized brush bristles and a voltage-balancing contactor are devised to increase cleaning efficiency and to prevent arc generation under live-line conditions, respectively. We confirmed its effectiveness through experiments.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1791-1793
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• 1996

This paper describes Thermal-Mechanical performance and Ultimate Mechanical-Strength test for the purpose of aging analysis of suspension insulator. The temperature difference of insulator surface according to the aging of suspension insulator brought out about $2^{\circ}C$ to $7-8^{\circ}C$ difference comparing with the atmospheric temperature. Quality standard and Mechanical-Strength of used suspension insulator deteriorate more remarkably than that of new suspension insulator. It is required that Thermal-Mechanical performance test standard be revised in the future. And it is described about the development prospect of polymer insulators

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.315-316
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• 2006

A new cleaning robot system for live-line tension insulator string was developed to prevent an insulator failure, which can have severe effects on national security as well as national industry and economy. The robot moves along the insulator string using the clamps installed on its two moving frames. Especially, unlike the existing cleaning robots using jets of water or water/air, the robot system adopts dry cleaning method using a rotating brush and a circular motion guide. This robot system has control architecture consisting of a master control unit and two slave control units. We confirmed its effectiveness through experiments.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.1
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• pp.16-22
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• 2003

While passing through the AC/DC section insulators installed at electric railroad catenary, some electric trains undergo mis-operation of main circuit breaker after AC/DC change-over operation. This paper provides insulation resistance measurements of AC/DC section insulators, which confirm the insulation levels of section insulators are below the standard of insulators. The insulation deterioration and pantograph arrangement on the electric train can produce voltage impression on section insulator which induces mis-operation of main circuit breaker To mitigate the insulation deterioration of the section insulator installed at underground railroads, the section insulators have been cleaned periodically, but section insulator structure should be modified to make the section insulator performance perfect. Based on the above analysis, effective modification method of AC/DC section insulator is provided.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.4
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• pp.417-423
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• 2008

For the evaluation in the safety of outdoor insulator, there are various methods such as: visual observation; voltage measurement; use of ultrasonic wave due to partial discharge; electric field measurement; use of infrared/ultraviolet sensor-type camera. However, many problems have been issued regrading the reliability of the evaluation test and safety of testing operation. Accordingly, the present study has investigated and analyzed the characteristics and mechanisms of the insulator deterioration, in order to obtain an optimal method for detecting poor insulator so that the reliability of power facilities can be enhanced. Besides, based on theoretical analysis of domestic and international detection methods for poor insulator, the reliability has been compared and evaluated quantitatively. As a result, it was shown that the corona camera would be the best choice for domestic workplace application in detecting poor insulator for enhancing the reliability of power transmission line.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.255-257
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• 2001

In this paper, the silicon rubber insulator for transmission line was experimented for 1,000 hours aging test in salt-fog condition. To evaluate and examine the aging properties of silicon rubber insulator for test, the leakage current of surface was measured. Also hydrophobicity and scanning electron microscopy were compared with initial and aged sample respectively Above results, we can confirm that the surface properties of silicon rubber insulator easily aged by salt-fog condition.

• Journal of the Korean Ceramic Society
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• v.19 no.3
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• pp.229-235
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• 1982

This paper deals with the electric insulator in terms of its toughness. The toughness is determined by the notched beam test and it is found that the toughness of electric insulator largely depends on the porosity as well as crystalline phases. This study also indicates that the Korean electric insulators have improved its toughness for last seven years and the recent products show comparable properties with imported insulator.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.11
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• pp.1199-1204
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• 2004

Most overhead transmission lines in Korea run over the mountain; however, only little study has been made for the effect of mountain fire on polymeric insulator for transmission lines, though the study is significantly required, Therefore, in this study, the authors observed the deformation of the sheds of the insulator under fire, varying the ignition time using artificial ignition testing equipment, and investigated electrical and mechanical characteristics of the insulator through dry withstand voltage test, impulse flashover test and tensile load test. As the results of the tests, the following conclusions were obtained, First, when the insulator was subjected to the fire, the electrical characteristics were slightly reduced, but there was no change on the mechanical characteristics, Secondly, the sheds and sheath of the insulator were not non-flammable but less-flammable. These two results show the high mechanical stability and durability of the insulator under severe fire condition, though the electrical characteristics can be deteriorated as the time that the insulator is subjected to fire, goes by.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.6
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• pp.648-654
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• 2003

Diamond MIS(Metal-Insulator-Semiconductor) diodes and MISFETs(Metal-Insulator-Semiconductor Field Effect Transistors) were fabricated by employing various fluorides as gate insulator, and their electrical properties were closely investigated by means of C-V measurements. The A1/BaF$_2$/diamond MIS structure exhibited outstanding electrical properties. The MIS diode showed a very low surface state density of ∼10$\^$10//$\textrm{cm}^2$ eV near the valence band edge, and the observed effective mobility(${\mu}$$\_$eff/) of the MISFET was 400 $\textrm{cm}^2$/Vs, which is the highest value obtained until now in the diamond FET. From the chemiphysical point of view, the above result might be explained by the reduction of adsorbed-oxygen on the diamond surface via strong chemical reaction by the constituent Ba atom in the insulator during the film deposition(Oxygen-Gettering Effect).