• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05a
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• pp.61-65
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• 2001

The conventional tracking testing as IEC-60587 is widely used in surface aging measurement of outdoor insulator because those testing can carry out very short time in Lab-testing. Also IEC-60587 testing is able to offer the standard judgement of relative degradation level of outdoor HV machine/system. Therefore it is very useful method compare to previous conventional tracking testing method and effective Lab-testing method. But surface discharges(SD) have very complex characteristics of discharge pattern so it is required estimation research to development of precise analysis method. In recent, the study of IRR-camera is carrying out discover of temperature of power equipment through condition diagnosis and system development of degradation diagnosis. In this study, SD occurred from procelain insulator, used 22.9[KV] distribution, is measured with partial temperature distribution in real time, the degradation grade of SD is analyzed through produced patterns in SD concentration according to applied time.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.09a
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• pp.28-33
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• 2001

In this paper, aging characteristics of outdoor silicone rubber insulator resulting from the acid rain have been investigated with regards to nitrate ion ($NO^{-1}_{3}$ ). For this purpose, silicone rubber was aged by immersing into the nitric solutions with different level pH during 1500 hours and various tests (tracking, tan $\delta$, breakdown voltage, SEM, EDS, contact angle) were performed. It was observed that the degradation was increased to pH 2.5 slightly and at pH 1.5 highly. And thus, it could be expected that there is certain critical point between pH 1.5 and 2.5, which leads to throught degradation.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1499-1501
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• 1994

This paper studies on the outdoor field test facilities which are established for weather-resist and mechanical-resist property teat of composite insulator. We have established measuring and data acquisition system for various test conditions -leakage current, temperature, humidity, wind direction, wind velocity and rainfall. The merry-go-round test and salt fog test have been studied in order to evaluate non tracking property of rubber material. Especially we have checked the relationship between hydrophobicity and outdoor exposure degree by contact angle measurement.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.196-199
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• 1996

In this paper, aging characteristics of outdoor silicone rubber insulator resulting from the acid rain have been investigated with regards to nitrate ion ($NO_3$). For this purpose, silicone rubber was aged by immersing into the nitric solutions with different level ph during 1500 hours and various tests(tracking, contact angle, $tan{\delta}$, breakdown voltage, SEM, EDS, FT-IR) were performed. It was observed that the degradation was increased to ph 2.5 slightly and highly at ph 1.5. And thus, it could be expected that there is certain critical point between ph 1.5 and 2.5, which leads to throught degradation.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.10
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• pp.465-472
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• 2002

This paper presents a study on the aging and recovery of HTV (high temperature vulcanized) silicone rubber used for outdoor insulators. UV irradiation, corona discharge and water immersion were employed as factors of the artificial aging. The effects of changes derived from these stresses on the tracking and arc resistance of silicone rubber were examined. We have investigated the aging phenomena of HTV silicone rubber by the above stresses using the surface energy calculation with contact angle measurement, solvent-extraction, and surface/volume resistivity and so on. These results showed that UV irradiation and corona discharge lead to nearly the same surface oxidation, but the percentage change of mobile low molecular weight by these stresses was different. Furthermore, the oxidized layer induced under UV irradiation restricted the recovery of hydrophobic surface. Water immersion little lowered hydrophobicity level and leaded to a loss of tracking and arc resistance. The degradation mechanism based on our results was discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05a
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• pp.23-28
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• 2000

Insulator systems using resin casting apparatus are useful to realize the high capacity, small size, and combined electric power equipments, and are expected to bring various advantages. In Korea, epoxy resin molded apparatus have been restricted to indoor uses till now. On the other hand, in Europe, molded insulators and transformers and so forth have been practically used since the former half of 1960's. Recently, investigation on epoxy resin materials and molded apparatus for outdoor use have ben intensively carried out. Probably, this is because electric power outdoor apparatus such as distribution transformer can be given multi-functions by using outdoor epoxy resin compound This study describes the trend on the development of epoxy mold transformers, and important technologies applied for outdoor use.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.2068-2069
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• 2007

This study describes a compairison leakage current properties between a polluted insulator and insulator subjected to salt polluted condition. Exposure tests at a sea coast test and the leakage current of insulators, climate conditions, and salt deposit density were measured during the tests. Appearance of leakage current for the insulator was affected by the humidity and the salt deposition on the surface. comparison of leakage current under salt polluted conditions. salt polluted test and humidity tests were carried out in laboratory using the same insulator profiles in oder to determine the leakage current patterns during critical conditions

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.558-559
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• 2005

Recently, 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. In this paper, the tracking property of polymer suspension insulator for power transmission is investigated with CEA tracking wheel test. The diagnosis of insulator sample in tracking test has been analyzed by leakage current, STRI Guide, SEM, FTIR and thermal image.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.66-68
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• 2001

Recently polymer insulators are being used for outdoor high voltage applications. Polymer insulators for transmission and distribution line have significant advantages over porcelain and glass insulators, especially for ultra-high voltage(UHV) transmission lines. Their advantages are light weight, vandalism resistance and hydrophobicity. In this paper, distribution polymer suspension insulator has been designed and investigated electric field distribution by FEM.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.119-122
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• 2000

Recently polymer insulators are being used for outdoor high voltage applications. Polymer insulators for transmission line have significant advantages over porcelain and glass insulators, especially for ultra-high voltage transmission lines. Their advantages are light weight, vandalism resistance and hydrophobicity. Polymer insulators are a relatively new technology, but their expected life is still unknown. Therefore these estimating technique are very important. Their life time is related to weathering and operating condition. Multi-aging test is requested because aging factor is occurred by multi-aging than unique aging. The aging test about polymer insulators have mainly carried out by IEC 61109. This paper presents multi-stress chamber experiments and tracking wheel test to examine the tracking and erosion performance of polymer insulator for transmission. Multi-stress testing is able to demonstrate deficiencies of polymer insulator materials and designs, including the nature of interfaces in insulation design. We have investigated IEC 61109 Annex C (5000h aging test) and CEA tracking wheel test as test methods of artificial accelerated aging. The aging degree of polymer insulator is estimated by leakage current, measurement of hydrophobicity degree, damage conditions of insulator surface, withstand voltage test etc.