• Title/Summary/Keyword: Breakdown probability

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Evaluation of Insulating Reliability in Epoxy Composites using Dielectric Breakdown Data (절연 파괴 데이터를 이용한 에폭시 복합체의 절연 신뢰도 평가)

  • Park, Geon-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.114-118
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    • 2005
  • In this study, the DC dielectric breakdown of epoxy composites used for molding material was experimented and then its data were simulated by Weibull distribution equation. From the analysis of Weibull distribution, it was confirmed that as the allowed breakdown probability was given by 0.1[%], the applied field value needed to be under 21.5[kV/mm].

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An Analysis of Insulating Reliability in Epoxy Composites for Molding Materials of PT

  • Yang, Jeong-Yun;Park, Geon-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.43-46
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    • 2001
  • The DC dielectric breakdown of epoxy composites used for transformer was experimented and then its data were simulated by Weibull distribution equation in this study. The more hardener increased the stronger breakdown strength at low temperature because of cross-linked density by the virtue of ester radical, and the breakdown strength of specimens with filler was lower than it of non-filler specimens because it was believed that the adding filler formed interface, charges were accumulated in it, the molecular mobility was raised, the electric field was concentrated, electrons were accelerated and then electron avalanche was early accomplished. From the analysis of Wei bull distribution equation, it was confirmed that as the allowed breakdown probability was· given by 0.1[%], the value of 'applied field was needed to be under 17.20[kV/mm].

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Estimation of Breakdown Properties in Nano-composites using Weibull Statistics (와이블 통계를 이용한 나노컴퍼지트 파괴강도의 평가)

  • Lee, Kang-Won;Lee, Hyuk-Jin;Park, Hee-Doo;Kim, Jong-Hwan;Shin, Jong-Yeol;Lee, Chung-Ho;Hong, Jin-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.285-286
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    • 2008
  • Recently, epoxy based nano-composites are being increasingly investigated for their electrical properties, since the introduction of nano fillers demonstrate several advantages in their properties when compared with the similar properties obtained for epoxy systems with micrometer sized fillers. We calculated scale and shape parameter using dielectric strength. In this paper, it is investigated that the allowable' breakdown probability of specimens is stable at some value using Weibull statistics. Therefore we found that breakdown probability of specimens is stable until 20 [%].

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Electrical Properties of the Epoxy Nano-composites according to Additive

  • Shin, Jong-Yeol;Park, Hee-Doo;Choi, Kwang-Jin;Lee, Kang-Won;Lee, Jong-Yong;Hong, Jin-Woong
    • Transactions on Electrical and Electronic Materials
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    • v.10 no.3
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    • pp.97-101
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    • 2009
  • The use of a filler material in epoxy composite materials is an essential condition for reducing the unit cost of production and reinforcing mechanical strength. However, the dielectric strength of insulators decreases rapidly due to interactions between the epoxy resin and filler particles. In contrast to existing composite materials, nano-composite materials have superior dielectric strength, mechanical strength, and enduring chemical properties due to an increase in the bond strength of the polymer and nano material, It is reported that nano-fillers provide new characteristics different from the properties of the polymer material. This study is to improve the insulation capability of epoxy resins used in the insulation of a power transformer apparatus and many electronic devices mold. To accomplish this, the additional amount of nano-$SiO_2$ to epoxy resin was changed and the epoxy/$SiO_2$ nano composite materials were made, and the fundamental electrical properties were investigated using a physical properties and an analysis breakdown test. Using allowable breakdown probability, the optimum breakdown strength for designing an electrical apparatus was determined. The results found that the electrical characteristics of the nano-$SiO_2$ content specimens were superior to the virgin specimens. The 0.4 wt% specimens showed the highest electrical properties among the specimens examined with an allowable breakdown probability of 20 %, which indicates stable breakdown strength in insulating machinery design.

Electrical Insulation Properties of Nanocomposites with SiO2 and MgO Filler

  • Jeong, In-Bum;Kim, Joung-Sik;Lee, Jong-Yong;Hong, Jin-Woong;Shin, Jong-Yeol
    • Transactions on Electrical and Electronic Materials
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    • v.11 no.6
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    • pp.261-265
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    • 2010
  • In this paper, we attempt to improve the electrical characteristics of epoxy resin at high temperature (above $80^{\circ}C$) by adding magnesium oxide (MgO), which has high thermal conductivity. Scanning electron microscopy (SEM) of the dispersion of specimens with added MgO reveals that they are evenly dispersed without concentration. The dielectric breakdown characteristics of $SiO_2$ and MgO nanocomposites are tested by measurements at different temperatures to investigate the filler's effect on the dielectric breakdown characteristics. The dielectric breakdown strength of specimens with added $SiO_2$ decreases slowly below $80^{\circ}C$ (low temperature) but decreases rapidly above $80^{\circ}C$ (high temperature). However, the gradient of the dielectric breakdown strength of specimens with added MgO is slow at both low and high temperatures. The dielectric breakdown strength of specimens with 0.4 wt% $SiO_2$ is the best among the specimens with added $SiO_2$, and that of specimens with 3.0 wt% and 5.0 wt% MgO is the best among those with added MgO. Moreover, the dielectric strength of specimens with 3.0 wt% MgO at high temperatures is approximately 53.3% higher than that of specimens with added $SiO_2$ at $100^{\circ}C$, and that of specimens with 5.0 wt% of MgO is approximately 59.34% higher under the same conditions. The dielectric strength of MgO is believed to be superior to that of $SiO_2$ owing to enhanced thermal radiation because the thermal conductivity rate of MgO (approximately 42 $W/m{\cdot}K$) is approximately 32 times higher than that of $SiO_2$ (approximately 1.3 $W/m{\cdot}K$). We also confirmed that the allowable breakdown strength of specimens with added MgO at $100^{\circ}C$ is within the error range when the breakdown probability of all specimens is 40%. A breakdown probability of up to 40% represents a stable dielectric strength in machinery and apparatus design.

Evaluation of Insulating Reliability in Epoxy Composites by Dielectric Breakdown Properties (절연 파괴 특성을 이용한 에폭시 복합체의 절인 신뢰도 평가)

  • 신철기;김용연;심재환;박건호;이준웅
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.310-312
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    • 1995
  • In order to evaluate insulating reliability in epoxy composites, breakdown data were experimented in the temperature range of 20[$^{\circ}C$]∼160[$^{\circ}C$]. From these data, various parameters which are used in Weibull distribution could be derived, and using them, the reliability on a breakdown probability was calculated.

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An Estimation of Breakdown Time of the Epoxy Composites according to Filler and Silane Treatment (충진제와 실란처리에 따른 에폭시 복합체의 파괴시간 예측)

  • Shin, Cheol-Gi
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.9
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    • pp.793-797
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    • 2007
  • In this paper, the long time breakdown characteristic of the epoxy composite, which is widely used in the insulation system for high voltage application, was estimated with Weibull distribution. In the procedure of the estimation, the short time breakdown characteristics for the epoxy composite specimens, which were made with the variation of hardener and/or filler, were tested firstly. Then the long time voltage-to-time test was implemented. Finally, the long time breakdown voltage of each specimen was estimated with the parameters obtained from the statistical treatment with Weibull distribution. Base on the results, it has been found that the optimal weight ratio of epoxy resin/hardener/filler that has the excellent long time breakdown characteristic was 100/100/65. It was due to the silane treatment which relieves the electric field at the interface between filler and epoxy.

Analysis of Insulating Reliability in Epoxy Composites using Weibull Distribution Equation (와이블 분포식을 이용한 에폭시 복합체의 절연 신뢰도 분석)

  • Park, No-Bong;Lim, Jung-Kwan;Park, Yong-Pil
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.813-816
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    • 2003
  • The dielectric breakdown of epoxy composites used for transformers was experimented and then its data were applied to Weibull distribution probability. First of all, speaking of dielectric breakdown properties, the more hardener increased, the stronger breakdown strength became at low temperature because of cross-linked density by the virtue of ester radical. The breakdown strength of specimens with filler was lower than it of non-filler specimens because it is believed that the adding filler forms interface and charge is accumulated in it, therefore the molecular motility is raised and the electric field is concentrated. In the case of filled specimens with treating silane, the breakdown strength become much higher. Finally, according to Weibull distribution analysis, reducing breakdown probability of equipment insulation lower than 0.1 % level requires the allowable field intensity values to be kept under 21.5 MV/cm.

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Analysis of Insulating Reliability in Epoxy Composites Using Weibull Distribution Equation (와이블 분포식을 이용한 Epoxy 복합체의 절연 신뢰도 해석)

  • 임중관;박용필;이준웅
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.8
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    • pp.647-651
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    • 2001
  • The dielectric breakdown of epoxy composites used for transformers was experimented and then its data were applied to Weibull distribution probability. First of all, speaking of dielectric breakdown properties, the more hardener increased, the stronger breakdown strength became at low temperature because of cross-linked density by the virtue of ester radical. The breakdown strength of specimens with filler was lower than it of non-filler specimens because it is believed that the adding filler forms interface and charge is accumulated in it, therefore the molecular motility is raised and the electric filed is concentrated. In the case of filled specimens with treating silane, the breakdown strength become much higher. Finally, from the analysis of weibull distribution, it was confirmed that to low allowed breakdown probability under 0,.1%, the applied field value needed to be under 21.5MV/cm.

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Prediction of Insulation Reliability and Breakdown Life in Epoxy Composites (에폭시 복합체의 절연신뢰도 및 파괴수명 예측)

  • 신철기;박건호;왕종배;김성역;이준웅
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.260-264
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    • 1996
  • In this study, the dieiectric breakdown of epoxy composites used for transformers was experimented and then its data were simulated by Weibull distribution probability . As a result. first of all, speaking of dielectric breakdown properties, the more hardener increased the stronger breakdown strength at low temperature, and the breakdown strength of specimens because it is believed that the adding filler farms interface and charge is accumulated in it, therefore the molecular motility is raised, the electric field is concentrated, and the acceleration of electron and the growth of electron avalanche are early accomplished. In the case of filled specimens with treating silane, the breakdown strength become much higher since the suggests that silane coupling agent improves interfacial combination and relays electric field concentration. Finally, from the analysis 7f weibull distribution. it was confirmed that as the allowed breakdown probability was given by 0.11[%].

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