• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.429-432
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• 2004

The demand for electric power keeps growing, and tends to be more effective. Polymer insulators have been manufactured for almost twenty years and the excellent insulation performance of polymer insulators is attractive. Polymeric materials are now widely used as a replacement for inorganic materials such as porcelain or glass for the outdoor insulation of high voltage insulation. GFRP has been used widely as a core materials for polymer insulators. This paper reports the mechanical properties of GFRP for insulators. The bending strength was simulated and evaluated according to the winding angle. The fiber orientation in GFRP has a great effect on the strength of GFRP because the strength of GFRP mainly depends on the strength of fiber. Results of simulated and evaluated strength of GFRP were compared each other. The simulated strength of GFRP rod was different from the evaluated strength. It was caused that the shear stress had a great effect on the strength of GFRP although the stress of parallel direction of GFRP was much higher.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.5
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• pp.643-648
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• 2013

In this study, degradation was observed by irradiating UV rays to the polymer insulators which have been widely used in outdoor electric power facilities. For an indoor accelerated UV test, 0.55 w/m2 of UV rays were applied using a xenon-arc method. A UV detection system with 65 ${\phi}mm$ in diameter, 100 mm in length and 1.0 of brightness (F/#) has been designed. Even though efflorescence on the surface of polymer insulators wasn't observed according to the accelerated UV test. UV rays were detected at around 50% and 40% of insulation breakdown in EPDM and silicone-type insulators respectively. As degradation continued because of an indoor accelerated UV test, breakdown voltage with which UV rays can be detected in an early stage decreased as well. A silicone polymer insulator would be severer than EPDM polymer insulator in terms of surface degradation because of UV strength against $V_m/V_{BD}$ was high in silicone polymer insulators. UV strength in silicone-type insulators increased at 1,000 $kJ/m^2$ because contact angle at the intial stage sharply decreased to from $113^{\circ}$ to $92.1^{\circ}$.

• Transactions on Electrical and Electronic Materials
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• v.16 no.2
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• pp.82-85
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• 2015

Mechanical and electrical properties of epoxy/silica microcomposites were investigated. The cycloaliphatic- type epoxy resin was diglycidyl 1,2-cyclohexanedicarboxylate and the curing agent was of an anhydride type. To measure the glass transition temperature (Tg), dynamic differential scanning calorimetry (DSC) analysis was carried out, and tensile and flexural tests were performed using a universal testing machine (UTM). Electrical breakdown strength, the most important property for electrical insulation materials, and insulation breakdown strength were also tested. The microcomposite with 60 wt% microsilica showed maximum values in mechanical and electrical properties.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.117-120
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• 1998

It is analyzed the erosing process of the polymeric insulator for outdoor use with the inclined plane method. Materials used are the different type of silicone rubber, they have the content of filler and component each other. As the content of filler added to improve the tracking and erosion resistance. It has the difference of electrical performance and erosion rate. The dry-band arc is also the parameter of accelerating erosion, and appear in the form of leakage current, and the activities of leakage current has a close relationship with the surface hydrophobicity. In this paper, the erosion growth is observed by measuring the time from the voltage application to the whole breakdown, and the erosion depth. In addition, it is measured the hydrophobicity and leakage current to be a cause of erosion by the erosion steps, studied SEM, EDX for observing the transformation of surface structure by erosing.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.6-9
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• 2001

In this research, a experiment was performed to evaluate the electrical properties of outdoor insulator with the pollution cycle method. Cycle test methods such as DCM of STRI, IEC 61109 compared with pollution cycle method. Using dimatic properties of Korea peninsula, we could get the optimal condition for the pollution cycle method. As the factor, clean and saline fog, voltage, rainfall and drying was chosen. The applied voltage is 13,2 kV, the salinity of salt solution was changed from 0.1 wt% to 1.5 wt% and one cycle is about 4 hours. To ensure the reproducibility and reliability, experiments repeated 4 times. The leakage current was measured with Lab VIEW and the ESDD was measured with brushwiping method. This experiment could ensure superiority of pollution cycle method which developed through the result of this experiment and we could know the relationship between ESDD, leakage current and relative humidity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.2
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• pp.188-193
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• 2007

Tracking and erosion of Poly Methyl Methacrylate (PMMA) and the suppression mechanism of alumina trihydrate were investigated in the present study The conventional testing as IEC-60587 is widely used in surface aging measurement of outdoor insulator those testing can carry out very short time for Lab testing. Also IEC-60587 testing is able to offer the standard judgement of relative degradation level of outdoor HV system. Therefore it is very useful method compare to previous conventional tracking 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 paper, SD occurred from IEC-60587 is measured with the surface temperature of weibull distribution in real time, the degradation grade of SD is analyzed through produced patterns in IEC-60587 using Infrared Radiation(IRR) camera.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.565-569
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• 1999

In these days, the silicone insulators have been increasingly studied and applied for outdoor insulators because it has superior characteristics than porcelain and glass insulators, which have been used for outdoor insulators. First of all, The excellent performance of the silicone rubber in polluted and wet conditions is attributed to the ability of the material to maintain the hydrophobicity of the surface in the presence of severe contamination and wet conditions. This is because of the presence of low molecular weight mobile fluid in the silicone rubber which diffuses to the surface and to above the contamination layer. But, the leakage current and some surface discharge occurs on surface of the composite polymeric insulation materials when the insulator is used for a long time with severe contaminative condition and it can lead the contamination flashover. So the leakage current and the discharge current are important to estimate the condition of the silicone rubber surface. In this paper, the average leakage current, the relation of surface discharge current and phase angle were study to investigate electrical conduction of silicone rubber surface with the salt fog condition.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.4
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• pp.30-37
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• 2002

This paper reports on the results of weathering test, tracking test and salt-fog test of various kinds of cycloaliphatic epoxy systems. UV irradiation dramatically induced the loss of surface hydrophobicity due to the chain scission attack at the surface under UV irradiation. It could be seen that samples containing an UV absorbent/antioxidant and a silicone oil additive have a good performance in weathering test, while ATH(alumina tri-hydrate) filled ones have high resistance against tracking failure than others. Under salt fog chamber test, specimens mixed with silicone oil are able to suppress leakage current development. It was thought that silicone oil mixed into cycloaliphatic epoxy system could lead to lower the surface energy and to retain hydrophobic properties for a long time, which are desirable for outdoor use.

• Journal of the Korean Institute of Rural Architecture
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• v.19 no.4
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• pp.57-65
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• 2017

Life quality in farming areas is declining these days on account of decrease in population with the outflow of young generations, advent of aging society, and also lack of social and physical infrastructure. To reverse this, the central and local governments have been devising policies in many ways; however, the vulnerable class in farming area suffering from financial difficulty is not supported with that properly. The results of applying insulation materials applicable to rural houses, EPS, e-board, and glass wool, actually to rural houses are summed as follows. EPS is the most inexpensive among the three installations in terms of material cost and expenses. The indoor and outdoor temperature difference increased from $0.9^{\circ}C$ to $2.5^{\circ}C$, and the temperature change reduced as $0.04^{\circ}C$. With e-board, the indoor and outdoor temperature difference increased from $3.3^{\circ}C$ to $7.5^{\circ}C$; however, the temperature change increased as $0.09^{\circ}C$. Unlike the other two methods, glass wool requires the additional installation of wooden frames. The material cost is highest, and the indoor and outdoor temperature difference increased from $1.1^{\circ}C$ to $8.0^{\circ}C$, and the temperature change reduced as $0.01^{\circ}C$. According to the results of measuring temperature, glass wool's temperature difference is measured to be the highest, but temperature change is found to be the most effective in EPS. Among the three insulation methods, EPS is the most economically advantageous as the material supply is easy and the cost is low. The material is easily processible, so ordinary town residents can install it easily, and it is effective at improving insulation performance, too. But this method cannot be applied when the house has walls that are not even. Also, as the insulator is thick, after the installation, the living space may be narrower as a result.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1232-1234
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• 1995

Specimem of silicone rubber used to make the weathersheds for High-Voltage composite insulator were aged in laboratory. The aging characteristics of silicone rubber have been assessed by compairing their hydrophobicity and electrical properties, before and after aging with weather ometer. Results show that their initial and time dependant characteristics are good.