• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 C
• /
• pp.1467-1469
• /
• 2002

This paper aims to investigate the characteristics of braided thermoplastic and thermosetting composite and pressure relief for polymer arrester. In general, braided composite has potential for improved impact and delamination resistance. Manufacturing processes of the braided composite could also be automated and could potentially lead to lower costs. Therefore, in consideration of characteristics of pressure relief for polymer arrester, the fabric pattern of braided composite was studied. And polymer arrester module was manufactured with braid.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
• /
• pp.315-316
• /
• 2005

This paper describes the AC accelerated ageing characteristics of zinc oxide varistors for the station class lightning surge arresters. ZnO varistors whose rated voltage were 3.27kV, 4.00kV, and 6.00kV were manufactured with general ceramic production methods. The power loss of sample A varistors rapidly increased and eventually showing the thermal run-away, but sample B and sample C varistors exhibited negative creep phenomena in power losses during the test.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
• /
• pp.317-318
• /
• 2005

This paper presents the analysis on the properties of porcelain insulators with the manufactured year. The domestic porcelain insulators manufactured in 1995, 1997, and 2002 and the imported one are prepared. The content of alumina was increased with the manufactured year, and the hardness of ceramic parts showed the same trend. Moreover, the distribution and the size of pore were more decreased and reduced on the junction parts between the glaze and the ceramic. Therefore, we concluded that the domestic porcelain insulators have been improved with the lapse of time.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 1993년도 추계학술발표회논문집
• /
• pp.97-102
• /
• 1993

The application of epxy composite materials for the outdoor insulating systems has some significant advan-tages compared with conventional inorganic materials, that is low weight in combination with high mechanical strength, small dimensions and design versatility. The paper describes the results of high voltage investigations carried out different aging types of epoxy resin insulator and silicone grease coating. The insulators have been exposed 3000 hours to weather-o-meter and 12 months to outdoor. In this connection, the main study of paper is form the basis of develop-ment of principal technologies of epoxy composites which ard: (1)manufacturing of insulator, (2)high vol-tage testing under dry and wet condition, (3)mechani-cal properties, (4)accelerated weather-ometer test and outdoor exposed, artificial polution.

• 대한전기학회논문지:전력기술부문A
• /
• 제55권10호
• /
• pp.433-439
• /
• 2006

This paper describes the characteristic evaluation of 154kV lightning arrester developed by domestic technology. To prove the protective ability of lightning arrester developed, various overvoltages were analyzed for A and B arrester were being used now at 154kV air and gas insulation substation, and for arrester developed. The results obtained by the various simulations show that the developed arrester has the effective protective ability and reducing ability of the overvoltage as A and B arrester, nevertheless there are somewhat differences among three kinds of arresters. Accordingly, it is evaluated that the arrester developed by domestic technology secured reliability can be installed actually at 154kV substation. In this paper, EMTP/ATP was used for simulation.

• 한국전기전자재료학회논문지
• /
• 제14권4호
• /
• pp.297-301
• /
• 2001

In this paper, the temperature distribution and thermal stress analysis of 50kVA pole cast resin transformer for power distribution are investigated by FEM program. The one body molding model (Model 1) and air duct model (Model 2) are designed and their temperature distribution are analysed. The temperature rise value is about 105.5 deg in the model 1 and 65.28 de in the model 2. The temperature change of secondary winding is more than primary winding according to load ratio. The concentration part of Von Mises Stress occurs at interface between glass fiber and epoxy.

• E2M - 전기 전자와 첨단 소재
• /
• 제8권2호
• /
• pp.217-223
• /
• 1995

In this paper, we investigated physical properties and electrical characteristics of the fluorocarbon that used as coolants for large power gas-insulated transformer. Volume resistivity of the fluorocarbon was .rho.=1.87*10$^{15}$ [.ohm.cm] at 1 atm, 27.deg. C. Dielectric constant was 1.86 and decreases as temperature increase. The breakdown voltage at 1 atm was higher than that of transformer oil. The breakdown voltage of fluorocarbon vapor was about 18kV when pressure in a test chamber increases over lkg/cm$^{2}$. When fluorocarbon was mixed with SF$_{6}$ gas, breakdown voltage of the mixed was higher than that of fluorocarbon. Then fluorocarbon leads to increase over 4kg/cm$^{2}$ in pressure as temperature increase. Therefore, when a gas-insulated transformer is manufactured, the design must be taken into consideration a high-pressure.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제52권8호
• /
• pp.359-364
• /
• 2003

Ageing characteristics of RTV coating materials by corona discharge have been studied. The hydrophobicity recovery of RTV coating materials with 300${\mu}{\textrm}{m}$ thickness was identical with a bulk silicone materials. The RTV coating materials hydrophobicity has been almost lost when its were discharged during 40 seconds by corona discharge of 10㎸, and recovered after about 45 hours. The resistivity of RTV coating materials has not been recovered after 45 hours, though after 80 hours the initiation resistivity value has been recovered up to 95%. There was no critical change of compounds(such as Si and Al) on RTV surfaces by the corona discharge treatment until 100 seconds. In the test of arc erosion, it was seen that the coating sample with silicone rubber as a base material have more longer burn-out time than other samples with FRP or glass base.

• E2M - 전기 전자와 첨단 소재
• /
• 제10권8호
• /
• pp.770-777
• /
• 1997

Some polymer materials including epoxy resin are being instead of porcelain for outdoor insulating materials such as insulators bushings cable terminators and surge arrester housing. And the largest problem to be overcomed is the tracking and erosion of the outdoor polymer material brought about by dry band arcing during prolonged exposure to contaminations. In this paper the effect of surface tension wettability flow rate of contaminants with varying surfactant content and frequency of applied voltage on the tracking breakdown of epoxy insulating materials were investigated. As the flow rate of contaminant is increased the surface resistivity is decreased and the leakage current is increased the time to tracking breakdown is decreased. It is found that time to tracking breakdown depends on the surface tension of contaminant that is difference of wettability. And as the frequency of applied voltage is increased time to tracking breakdown decreased.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 A
• /
• pp.491-493
• /
• 2001

This paper describes the effect of lightning current on combination transmission line. In the paper, an lightning current which can generate 2/80[${\mu}s$]. 20[kA] - 40[kA] waveform is modeled in ATPDraw. The lightning current invaded to the overhead power transmission line propagates to the underground power cable. The simulation was performed to analyze the effect of arrester location and overvoltage occurred in power cable.