• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.392-396
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• 2004

Experimental equipments for long-term outdoor tests of EHV insulators in outdoor were constructed. The testing insulators have been energized with 89 [kV] phase-to-ground AC voltage under identical condition at station, and the investigation was carried out for leakage current and various environments such as temperature, relative humidity and wind velocity. The test results of leakage current wave trends have forms on distorted waves including harmonics. The porcelain and glass insulators have low leakage current in case of daytime because moisture and humidity have relative low values. In comparison with these conditions, high leakage current was shown at dawn and rainy day due to high humidity. However, leakage current of polymer insulators was shown approximately $129[{\mu}m]$ without relation to the weather due to hydrophobicity on their surface.

• Polymer Science and Technology
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• v.26 no.3
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• pp.232-237
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• 2015

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.3
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• pp.127-131
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• 2005

Big fire such as mountain fire may cause the prevention of the functions of the overhead cables and insulators, which may affect the operation of the transmission lines. In the worst case, this kind of disaster may have a huge effect on the whole industry of a country. However, the study on the effect of the mountain fire on the transmission line is very rare. Therefore, in order to understand the effect of the mountain fire on the polymeric insulator for transmission lines, the author observed the deformation of the sheds of the polymeric insulators and the change of the discs of the porcelain insulators under fire, varying the ignition time using the artificial ignition testing equipment which simulates the mountain fire, and investigated the electrical and mechanical characteristics of the insulators after the ignition test. For the test, the miniature insulators made of polymeric material and porcelain have been utilized. As the result, the following conclusions were obtained. First, the porcelain insulator was degraded in electrical characteristics when the insulator was subjected to the fire for approximately 5 minutes; whereas, the polymeric insulator was not degraded though there were some damage on its sheds. Second, after 20 minute exposure to the fire, the polymeric insulator lost a lot of parts of sheds, but the electrical characteristics was lowered by around $20\%$, but the porcelain insulators were electrically degraded by more than $80\%$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.539-542
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• 2003

Recently, the polymer insulators which are being used for high voltage applications have some advantages such as light weight, small size, vandalism resistance, hydrophobicity and easy making process. During outdoor service of polymer insulators, the surface of the insulating material is frequently subjected to moisture and contamination which lead to the well known phenomenon of dry band arcing. Their tracking resistance, erosion resistance, end sealing and shed design are very important because dry band arcing causes degradation of polymer surface. The shape design of porcelain insulator is formalized but design standard for polymer insulator is no standardized up to now, much research is necessary in real condition. In this paper, the aging property of polymer insulator with shed shape(regular, alternative type) is analyzed through numerical analysis, CEA(canadian electricity association) tracking wheel test and IEC 61109 Annex C.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.233-236
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• 2004

Recently, the polymer insulators that are used for high voltage applications have some advantages such as light weight, small size, vandalism resistance, hydrophobicity and easy making process. During outdoor service of polymer insulators, the surface of the insulating material is frequently subjected to moisture and contamination that lead to dry band arcing. Their tracking resistance, erosion resistance, end sealing and shed design are very important because dry band arcing causes degradation of polymer surface. The shape design of porcelain insulator is formalized but design standard for polymer insulator is no standardized up to now, much research is necessary in real condition. In this paper, the surface and tracking properties of polymer suspension insulator for power transmission is investigated with ICP-AES, SEM, EDX, tracking wheel test and flashover voltage test. The diagnosis of insulator sample in tracking test hass been analyzed by leakage current STRI Guide and thermal image.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.1
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• pp.63-67
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• 2021

In this paper, we investigated the surface properties of polymer insulators to improve electrical insulation performance. First, after washing the polymer insulator in various ways, its contact angle was increased, thereby improving the hydrophobic properties and electrical insulation properties. In addition, TiO2 thin films, which have been used as a photocatalytic material and have been applied to the polymer insulator surface of to enhance the surface and electrical insulating properties. For the sputtering method, the contact angle after coating the TiO2 thin film increased with increasing RF power, but it was lower compared to that before coating, indicating that the hydrophobic properties of the surface were slightly deteriorated. Consequently, the electrical properties of the polymer-insulating material were maintained or improved after the TiO2 thin-film coating.

• Design & Manufacturing
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• v.6 no.2
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• pp.12-16
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• 2012

In this study, an injection mold is made to produce polymer line post insulators. FRP (fiber reinforced plastics) is covered by silicone housing. In injection molding process, chances for offcenter are 60 percent. Given the structure of the product, offcenter occurs owing to the imbalances in positions of gates and improper -designs of cores and jigs. This study focuses on mold modifications and improvements.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.500-504
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• 2004

This research is about the result of leakage current waveform about the situation of surface leakage current and environmental changes(Salt fog, clean fog and rain) by EPDM polymer insulators' amount of salt. The researcher presents the result of changing about fundamental harmonic, 3rd harmonic and 5th harmonic from starting point of supplying power to flashover. In this study, researched environmental affects (clean fog, salt fog and .am) about surface aging of polymer insulators and used frequency spectrum of leakage current waveform to develop the diagnostic technique of surface aging. When amount of salt contents changed, surface aging stage and the degree of aging (distortion factor) about 3rd and 5th harmonir waveform on low frequency harmonic wave. The distortion factor which is harmonic percentage about basic harmonic is important pointer to evaluate the surface condition of polymer insulators.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.4
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• pp.147-152
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• 2008

This paper describes the breakdown poperties of porcelain and polymer insulators using the UV camera. The experiment was carried out using condition of voltage at the KS C IEC 60060-1(2006). As these results, corona discharge in porcelain insulator was generated the weakness point of insulator union. And the corona discharge of polymer insulator happened in union of power source. Also, we could confirm easily weakness part of these insulators by ultraviolet image through the corona discharge. Besides, in the comparison with the exciting technique of ultrasonic detection, it confirmed that deterioration steps are corrected. These steps are possible to judge the deterioration of power facilities through reliable date. Hereafter, this study as the diagnostic technology suitable for the sites is used.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.254-259
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• 2005

Big fire such as mountain fire my cause the prevention of the functions of the overhead cables and insulators, which may affect the operation of the transmission lines. Therefore, in order to understand the effect of the mountain fire on the polymeric insulator for transmission lines, the author observed the deformation of the sheds of the polymeric insulators and the change of the discs of the porcelain insulators under fire, and investigated the electrical and mechanical characteristics of the insulators after the ignition test. As the result the following conclusions were obtained. First, the porcelain insulator was degraded in electrical characteristics when the insulator was subjected to the fire for approximately 5 minutes; whereas, the polymeric insulator was not degraded though there were some damage on its sheds. Second, after 20 minute exposure to the fire, the polymeric insulator lost a lot of parts of sheds, but the electrical characteristics was lowered by around 20%, but the porcelain insulators were electrically degraded by more than 80%.