• Journal of the Korean Solar Energy Society
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• v.22 no.1
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• pp.73-80
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• 2002

This is study of the planning of thermal insulation to prevent heat loss in a basement, is aimed at investigating the heat loss from the basement space and basement structures. The results analyzed in these researches are as follows; To analyze the heat loss from basement structures, this study experimented on the heat flow phenomenon of a non-insulation structure and two insulation structure models. From the result, the interior surface temperature of two insulation structures(B, C, model) showed an equal temperature, but the interior surface temperature of a non-insulation structure (A model) is different from the two models, Therefore, we understand that the insulator constructed in the basement structure makes a role of preventing the heat loss from the basement. In addition, the exterior surface temperature of two insulation structure models showed an equal temperature. Specially, judging from the temperature difference of C model. we understand that the performance of insulator is low under the definite depth of underground. The thermal insulation design should be constructed under the definite depth of underground considering outdoor and building conditions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.62-65
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• 2001

The effects of accelerated UV radiation on EPDM used for a polymeric insulator were investigated by contact angle, surface voltage decay after corona charging, SEM-EDX, ATR-FTIR and XPS. EPDM occurs as loss of hydrophobicity by UV treatment, which followed by surface cracking and chalking. The surface voltage decay on UV-treated EPDM show that the shorter decay time corresponded to the treated samples with a longer UV exposure time. The surface oxygen and aluminum content were found to increase and carbon decrease, as is observed in EDX analysis. The ATR-FTIR and XPS indicated that C-C and C-H groups decreased and the highly oxidized carbon bonds such as C-O, C=O and O-C=O increase with time. Also, the effects of surface charges on hydrophobicity based on our results is discussed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.2
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• pp.183-187
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• 2007

Fractal mathematics is being highlighted as a research method for classification of image. But the application of Fractal dimension(FD) has been requited the complicated calculation method because of its complex repetition progressing. In this paper, it has been developed the new approach method to express the Fractal Dimension(FD) for aging level calculation and estimation system of outside insulator using special image processing algorithm. As a result after FD testing, the recognized aging estimation of FD has a very characteristics compared to the conventional visual inspection.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1969-1971
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• 2000

This paper presents a data acquisition and analysis program modules that has been developed using the Labview program. These program modules can use to acquire and analyze leakage current data of insulator under different contamination conditions. The experimental hardware made up salt fog chamber, AC/DC power supply, transducer (shunt resistor), measurement devices and PC with the GPIB (General Purpose Interface Bus). And analysis program modules can calculate pulse level count, accumulated charge, average leakage current, power spectrum, and harmonics. The result of applying these analytical program modules to polymeric insulator is available for evaluation of leakage current characteristic of outdoor insulators.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.144-147
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• 2000

The effect of accelerated aging test on ethylene-propylene-diene monomer(EPDM) rubber used for outdoor insulation was studied by X-ray photoelectron spectroscopy(XPS), scanning electron microscope(SEM), FFT spectrum alalysis, and electrical pulse counts using PC by oscilloscope(300 MHz). In electrical alalysis, FFT spectrum analysis indicated arcing caused a significant increase in the third harmonic content of the leakage current of polluted insulator. Also, pulse counts increased as aging time. The surface oxygen and aluminum content were found to increase and that of carbon and nitrogen were found to decrease with time. The detailed XPS analysis indicated that the concentration of carbon in C-C decreased and concentration of highly oxidized carbons increased with time, which was due to the oxidation of EPDM rubber polymer SEM analysis indicated that crack and erosion of EPDM rubber occurred with time.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1578-1580
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• 1999

Silicone rubber is being used for the housing material of outdoor high voltage insulators such as composite insulator, bushing, surge arrestor and cable terminator because of good tracking and erosion resistance, good hydrophobicity and recovery of hydrophobicity, and chemical stability. In this paper, tracking and erosion resistance of silicone rubber having fluids and different ATH contents were examined. Fluids were selected under the consideration of their molecular weight and chemical structure, expecting the high migration rate, the good pollutant encapsulation, and the long period with good hydrophobicity. Good tracking and erosion resistance and arc resistance have been achieved for the silicone rubber above ATH content 130 phr.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05b
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• pp.132-136
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• 2002

In this paper, aging characteristics of outdoor silicone rubber insulator resulting from the acid rain have been investigated with regards to nitrate ion $({NO_{3}}^{-1})$. 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.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.7
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• pp.340-345
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• 2001

Because they have superior insulating properties and lower in price than their ceramic equivalents, polymeric insulators have been used in outdoor insulators. But polymeric insulators mainly using in an heavy contamination area of outdoor could be easily attached to contaminants such as salt and by-products of industrial processes. To understand its effect on contaminants adhered to these insulators, we dismounted polymeric insulators adhered contaminant in the field, and evaluated its electrical characteristics, CA, and ESDD. We also manufactured slurry mixed by some kaolin and salt for the artificial contamination test and measured the degree of contaminant, AC leakage current for these contaminated samples. Consequently, the adhered contaminants to its surface is likely to be affected the performance of insulation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.153-156
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• 2000

To reduce the maintenance expense, and the possibility of electric outage and accident, we should optimize the outdoor insulation system. And for the optimization, accurate measurement for the degree of contamination with climatic conditions, such as wind, rain, and drought, should be carried. However the classical measuring method, brush wiping, has some problems in the aspect of man power, reliability, and expense. In this paper, we propose two type apparatus, which could detect the degree of contamination on insulators in outdoor insulation system, such as transmission and distribution line insulator and bushing. One use the leakage current, and the other use the oscillating frequency to check the degree of contamination. To avoid the oxidation of electrode AC source, and the low degree of contamination was applied. From the result of this investigation we could get the good relationship between the degree of contamination and the leakage current and oscillating frequency

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.1
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• pp.39-45
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• 2002

To determine the representative pollution degree of outdoor insulators during the drought season, we should make an investigation on the long-term accumulation characteristics of contaminants. As the contamination mechanism of outdoor insulator is extremely depend on the climatic condition, there is a large difference between the research result of Japanese utilities. So based on the difference of precipitation of the Korea and Japan, we could say that the accumulation characteristics of the countries have a significant difference. But, based on the result of Japan, the accumulation property of contaminants was ignored in KEPCO\`s specification. So, to determine the accumulation characteristics of Korea, we measured the 2 and 3 month ESDD with brush wiping method and make a statistical analysis on measured data. And, from the results, we understood the accumulation characteristics of Korea and the influence of topographical condition on the distribution characteristics of salt contaminants. coast.