• 제목/요약/키워드: Dielectric breakdown

검색결과 280건 처리시간 0.23초

폴리에틸렌의 절연파괴와 그의 온도 및 두께의존성 (A Study on Thickness and Temperature Dependence of Dielectric Breakdown in Polyethylene)

  • 김점식;이종범;정우교;김미향;박대희
    • 대한전기학회:학술대회논문집
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    • pp.1388-1390
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    • 1995
  • The characteristic of dielectric breakdown in solid insulating material dominates the reliability and safety of power equipment and affects directly to its life. In this point of view, the thickness and temperature dependence of dielectric breakdown strength and mechanism of dielectric breakdown in low density polyethylene which has been employed widely as insulating material have been technically reviewed by examinations of thermal property. The dielectric breakdown strength depending on its thickness was measured 2.6[MV/cm] at the thickness of 20[${\mu}m$] and 1.9[MV/cm] at the thickness of 75[${\mu}m$] based on ambient temperature of 30[$^{\circ}C$]. It is shown the temperature dependence that dielectric breakdown strength decreases in linear as the thickness increases. The dielectric breakdown strength depending on temperature was measured 2.6[MV/cm] at the temperature of 30[$^{\circ}C$], 1.6[MV/cm] at 60[$^{\circ}C$] and 1.3[MV/cm] at 90[$^{\circ}C$] based on the thickness of 20[${\mu}m$]. As the ambient temperature increases, the temperature dependence is shown that a very large drop is occurred up to temperature of 60[$^{\circ}C$] and a very small drop is discovered over 60[$^{\circ}C$].

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중, 고압용 적층 세라믹 캐패시터 제작 및 분석 (Fabrication and Analysis of Multilayer Ceramic Capacitors for Medium and High Voltage)

  • 윤중락;김민기;이헌용;이석원
    • 한국전기전자재료학회논문지
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    • v.18 no.8
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    • pp.685-689
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    • 2005
  • In the fabrication and design of MLCCs (Multilayer Ceramic Capacitors) with Ni inner electrode for medium and high voltage, reliability and dielectric breakdown mode have been investigated. For thickness of green sheet, the relationship between the rated voltage versus the thickness of green sheet. Increasing the thickness of green sheet increases the dielectric breakdown voltage. However, a practical limit to this linear relationship occurs at 30 urn and above. As the thickness of green sheet increased, dielectric breakdown voltage and weibull coefficient is increased, but abruptly decrease at 30 urn and 36 urn. When 24 urn of green sheet thickness, weibull coefficient and dielectric breakdown voltage were 13.58 and 70 V/um respectively. The results enabling the MLCCs to demonstrate high levels of reliability at medium and high voltage.

전기 기기용 봉지 및 함침 에폭시 복합 재료의 내열성 및 절연파괴 특성 개선에 관한 연구 (A study on the improvement of thermostability and dielectric breakdown strength for packaging and impregnating epoxy composite materials for electrical machines and apparatus)

  • 김명호;김재환
    • E2M - 전기 전자와 첨단 소재
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    • v.7 no.6
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    • pp.527-533
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    • 1994
  • In this study, it was studied on dielectric breakdown strength and thennostability properties due to the structure variation of matrix resin and treatment of coupling agent of epoxy insulating materials. The interpenetrating network structure was formed by simultaneous heating curing the epoxy resin with single network structure and the methacrylic acid resin. Also inner structure was observed and the glass transition temperature was measured on these three type specimens. Dielectric breakdown properties were investigated by applying DC, AC and impulse voltage. As a result, the glass transition temperature and the dielectric breakdown strength of specimen with interpenetrating network structure was more higher than another two type specimens.

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Epoxy/SiO$_2$복합재료의 계면 처리 효과에 따른 절연 파괴 특성 개선에 관한 연구 (A Study on Improvement of Electric Breakdown Properties due to Interface Treatment Effect of Epoxy/SiO$_2$ Composite Materials)

  • 김명호;박창옥;박재준;김경환;김재환
    • 한국전기전자재료학회:학술대회논문집
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    • pp.102-104
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    • 1990
  • In this paper, we studied and investigated as to temperature dependence of dielectric breakdown properties, and the dielectric breakdown properties, and deterioration-proof properties due to interface treatment effect. In the result, we knew that temperature dependence of dielectric breakdown strength due to filler content was decreased, identified that D.C. dielectric breakdown strength was improved at the filler content 50[%]. When the D.C. voltage was applied to the non silane and silane treated specimens deal with mechanical deterioration, the dielectric breakdown strength was improved at the 150[%].

Epoxy 복합재료의 망목구조 변화에 따른 임펄스 절연파괴 특성 (Impulse Dielectric Breakdown Characteristics due to Network Structure Variation of Epoxy Composites)

  • 이덕진;김경환;김명호;손인환;김탁용;김재환
    • 한국전기전자재료학회:학술대회논문집
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    • pp.164-167
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    • 1997
  • A series of interpenetrating polymer networks(IPN) based on Epoxy, MA and PU were synthesized in order to improve withstand voltage properties of Epoxy resin. Dielectric breakdown characteristics are investigated for six types of specimens. As a result, it was found that impulse voltage dielectric breakdown characteristic of SIN specimen was the most excellent. It was also found that SIN specimens were stronger than anything else in scanning electron microscopy. On the other hand, as a result of consideration of dielectric breakdown strength change according to adding fi1ter, it was confirmed that the decrease of dielectric breakdown strength are controlled slightly by IPN method.

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다결정 및 다층구조 $BaTiO_3$ 박막의 Time-Dependent Dielectric Breakdown 특성 (Time-Dependent Dielectric Breakdown of a Polycrystalline and a Multilayered $BaTiO_3$ Thin Films)

  • 오정훈;송만호;이윤희;박창엽;오명환
    • 대한전기학회:학술대회논문집
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    • pp.1526-1528
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    • 1996
  • The dielectric reliability of a polycrystalline and a multilayered $BaTiO_3$ thin films was evaluated using a time-zero dielectric breakdown (TZDB) and a time-dependent dielectric breakdown (TDDB) techniques. The $BaTiO_3$ thin films were prepared by rf-magnetron sputtering technique on ITO-coated glass substrates. In case of the multilayered $BaTiO_3$ thin film, the dielectric breakdown histogram, which was obtained from the TZDB measurements, showed a typical Weibull distribution. While in case of polycrystalIine $BaTiO_3$ thin film, a randomly distributed dielectric breakdown histogram was observed. The TDDB results of the multilayered $BaTiO_3$ thin film guaranteed about $10^5$ hours-operation under the stress field of 1 MV/cm.

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변압기 오일에 자성나노입자 첨가에 따른 절연파괴전압 특성변화에 관한 실험적 연구 (Experimental Study on the Dielectric Breakdown Voltage with the Addition of Magnetic Nanoparticles in a Transformer Oil)

  • 서현석;이원호;이세희;이종철
    • 대한전기학회:학술대회논문집
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    • pp.1538-1539
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    • 2011
  • In this study, we have investigated the dielectric breakdown by measuring AC (60Hz) breakdown strength of the fluids in accordance with IEC 156 standard and have compared the results with references. It was found that the dielectric breakdown voltage of pure transformer oil is around 12 [kV] with the gap distance of 1.5mm between electrodes. In case of our transformer oil based magnetic fluids with 0.1% < ${\Phi}$(volume concentration of magnetic particles) <0.6%, the dielectric breakdown voltage shows above 30 [kV], which is 2.5 times higher than that of pure transformer oil. It can be explained by the changed ionization process by adding nanoparticles in pure transformer oil, which is due to trapped fast electrons and slow negative nanoparticles. Moreover, in case of the fluid with applied magnetic field, the dielectric breakdown voltage increases above 40 [kV], which is 3.3 times higher than that of pure transformer oil.

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거칠기에 따른 반도전-절연 계면층에서 접착특성과 절연성능 (Adhesion and Electrical Performance by Roughness on Semiconductive-Insulation Interface Layer of Silicone Rubber)

  • 이기택;황선묵;홍주일;허창수
    • 한국전기전자재료학회:학술대회논문집
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    • pp.78-81
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    • 2004
  • In this paper, the effect of adhesion properties of semiconductive-insulating interface layer of silicone rubber on electrical properties was investigated. Surface structure and adhesion of semiconductive silicon rubber by surface asperity was obtained from SEM and T-peel test. In addition, ac breakdown test was carried out for elucidating the change of electrical property by roughness treatment. From the results, Adhesive strength of semiconductive-insulation interface was increased with surface asperity. Dielectric breakdown strength by surface asperity decreased than initial Specimen, but increased from Sand Paper #1200. According to the adhesional strength data unevenness and void formed on the silicone rubber interface expand the surface area and result in improvement of adhesion. Before treatment Sand Paper #1200, dielectric breakdown strength was decreased by unevenness and void which are causing to have electric field mitigation small. After the treatment, the effect of adhesion increased dielectric breakdown strength. It is found that ac dielectric breakdown strength was increased with improving the adhesion between the semiconductive and insulating interface.

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MgO를 첨가한 에폭시 나노 컴퍼지트의 절연파괴강도 온도의존성 (Temperature Dependence on dielectric breakdown strength of Epoxy Nano-Composites depending on MgO)

  • 정인범;한현석;이영상;조경순;신종열;홍진웅
    • 한국전기전자재료학회:학술대회논문집
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    • pp.48-48
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    • 2010
  • In this paper, we have investigated temperature dependence of dielectric breakdown voltage at epoxy with added nano-filler(MgO), which is used as a filler of epoxy additives for HVDC(high voltage direct current) submarine cable insulating material with high thermal conductivity and restraining tree to improve electrical properties of epoxy resin in high temperature region. In order to find dispersion of the specimen, the cross sectional area of nano-composite material is observed by using the SEM(Scanning Electron Microscope) and it is conformed that each specimen is evenly distributed without the cohesion. As a result, it is confirmed that the strength of breakdown of all specimen at 50 [$^{\circ}C$] decreased more than that of the dielectric breakdown strength at room temperature. When temperature increases from 50 [$^{\circ}C$] to 100 [$^{\circ}C$], we have confirmed that breakdown strength of virgin specimen decreases, but specimens with added MgO show constant dielectric breakdown strength.

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카본블랙 첨가 PMC(Polyethylene Matrix Composites)의 문턱스며들기(Percolation Threshold)와 절연파괴 강도 임계지수 (Percolation Threshold and Critical Exponent of Dielectric Breakdown Strength of Polyethylene Matrix Composites added Carbon Black)

  • 신순기
    • 한국재료학회지
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    • v.21 no.9
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    • pp.477-481
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    • 2011
  • Composites of insulating polyethylene and carbon black are widely used in switching elements, conductive paint, and other applications due to the large gap of resistance value. This research addresses the critical exponent of dielectric breakdown strength of polymer matrix composites (PMC) made with carbon black and polyethylene below the percolation threshold (Pt) for the first time. Here, Pt means the volume fraction of carbon black of which the resistance of the PMC is transferred from its sharp decrease to gradual decrease in accordance with the increase of carbon-black-filled content. First, the Pt is determined based on the critical exponents of resistivity and relative permittivity. Although huge cohesive bodies of carbon black are formed in case of being less than the Pt, a percolation path connecting the conducting phases is not formed. The dielectric breakdown strength (Dbs) of the PMC below Pt is measured by using an impulse voltage in the range from 10 kV to 40 kV to avoid the effect of joule heating. Although the observed Dbs data seems to be well fitted to a straight line with a slope of 0.9 on a double logarithm of (Pt-$V_{CB}$) and Dbs, the least squares method gives a slope of 0.97 for the PMC. It has been found that finite carbon-black clusters play an important role in dielectric breakdown.