• Title, Summary, Keyword: Dielectric breakdown

Search Result 624, Processing Time 0.049 seconds

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

  • Kim, Jeom-Sik;Lee, Jong-Bum;Jung, Woo-Kyo;Kim, Mi-Hang;Park, Dae-Hee
    • Proceedings of the KIEE Conference
    • /
    • /
    • pp.1388-1390
    • /
    • 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[$^{\circ}C$].

  • PDF

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

  • Oh, Jeong-Hoon;Song, Man-Ho;Lee, Yun-Hi;Park, Chang-Yub;Oh, Myung-Hwan
    • Proceedings of the KIEE Conference
    • /
    • /
    • pp.1526-1528
    • /
    • 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.

  • PDF

A Study on the Dielectric Breakdown voltage and Transparency of Dielectric Layer in AC PDP (AC PDP 유전층의 절연파괴 전압과 투명도에 관한 연구)

  • Park, Jeong-Hu;Lee, Seong-Hyeon;Kim, Gyu-Seop;Son, Je-Bong;Jo, Jeong-Su
    • The Transactions of the Korean Institute of Electrical Engineers C
    • /
    • v.48 no.1
    • /
    • pp.39-44
    • /
    • 1999
  • The dielectric layers in AC plasma display panel(PDP) are essential to the discharge cell structure, because they protect metal electrodes from sputtering by positive ion bombarding in discharge plasma and form a sheath of wall charges which are essential to memory function of AC PDP. This layer should have high dielectric breakdown voltage, and also be transparent because the luminance of PDP is strongly correlated this layer. In this paper, we discussed the dielectric breakdown voltage and transparency of the dielectric layer under various conditions. As a result, on the $15\mum$ thickness, the minimum dielectric breakdown voltage was 435V and the transmission coefficient was about 80% after $570^{\circ}C$ firing process. It can be proposed that the resonable dielectric thickness in AC PDP is $15\mum$ because it has about 75V margin on the maximum applied voltage.

  • PDF

The AC, DC Dielectric Breakdown Characteristics according to Dielectric Thickness and Inner Electrode Pattern of High Voltage Multilayer Ceramic Capacitor (고압 적층 칩 캐패시터의 유전체 두께 및 내부전극 형상에 따른 AC, DC 절연 파괴 특성)

  • Yoon, Jung-Rag;Kim, Min-Kee;Lee, Seog-Won
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.21 no.12
    • /
    • pp.1118-1123
    • /
    • 2008
  • High voltage multilayer ceramic capacitors (MLCCs) are classified into two classes-those for temperature compensation (class I) and high dielectric constant materials (class II). We manufactured high voltage MLCC with temperature coefficient characteristics of C0G and X7R and studied the characteristics of electric properties. Also we studied the characteristics of dielectric breakdown voltage (V) as the variation of thickness in the green sheet and how to pattern the internal electrodes. The dielectric breakdown by electric field was caused by defects in the dielectric materials and dielectric/electrode interface, so the dielectric thickness increased, the withstanding voltage per unit (E) thickness decreased. To overcome this problem, we selected the special design like as floating electrode and this design affected the increasing breakdown voltage(V) and realized the constant withstanding voltage per unit thickness(E). From these results, high voltage application of MLCCs can be expanded and the rated voltage can also be develop.

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
    • /
    • /
    • pp.114-118
    • /
    • 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].

  • PDF

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

  • 이덕진;김경환;김명호;손인환;김탁용;김재환
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.164-167
    • /
    • 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.

  • PDF

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

  • 김명호;김재환
    • Electrical & Electronic Materials
    • /
    • v.7 no.6
    • /
    • pp.527-533
    • /
    • 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.

  • PDF

Simulation on Surface Tracking Pattern using the Dielectric Breakdown Model

  • Kim, Jun-Won;Roh, Young-Su
    • Journal of Electrical Engineering and Technology
    • /
    • v.6 no.3
    • /
    • pp.391-396
    • /
    • 2011
  • The tracking pattern formed on the dielectric surface due to a surface electrical discharge exhibits fractal structure. In order to quantitatively investigate the fractal characteristics of the surface tracking pattern, the dielectric breakdown model has been employed to numerically generate the surface tracking pattern. In dielectric breakdown model, the pattern growth is determined stochastically by a probability function depending on the local electric potential difference. For the computation of the electric potential for all points of the lattice, a two-dimensional discrete Laplace equation is solved by mean of the successive over-relaxation method combined to the Gauss-Seidel method. The box counting method has been used to calculate the fractal dimensions of the simulated patterns with various exponent $\eta$ and breakdown voltage $\phi_b$. As a result of the simulation, it is found that the fractal nature of the surface tracking pattern depends strongly on $\eta$ and $\phi_b$.

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

  • Yoon, Jung-Rag;Kim, Min-Ki;Lee, Heun-Young;Lee, Serk-Won
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.18 no.8
    • /
    • pp.685-689
    • /
    • 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.

A Study on the Dielectric Strength in Section of Winding in SF6 Gas Transformer ($SF_6$ 가스절연변압기에서 권선의 섹션에 대한 절연내력 연구)

  • Heo, U-Haeng;Ha, Yeong-Sik;Hong, Jeong-Pyo;Kim, Gyu-Tak
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.49 no.3
    • /
    • pp.152-158
    • /
    • 2000
  • This paper deal with the experimental discussion about the impulse and AC dielectric strength of SF6 gas insulated transformer. Test sample is measured the dielectric breakdown voltage about modeling of the first and second section which is the weakest for surge voltage. The AC breakdown voltage is appeared 1.4 times than impulse breakdown voltage, so we can estimate that the impulse breakdown voltage is severe to AC breakdown voltage, and when the impulse is applied, in case of lmm tapping with Nomex paper, the characteristics of dielectric breakdown voltage is same to that in oil immersed transformer when SF6 gas pressure is 2.2kg/$cm^2$G.

  • PDF