• Title/Summary/Keyword: cable aging

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Life Expectancy for Power Cable Insulation(XLPE) Using Statistical Method (통계적 기법을 이용한 전력 케이블 절연층(XLPE)의 수명 예측)

  • 이승엽;조대희;이인호;박완기
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.57-61
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    • 1999
  • Electrical stress makes insulating materials aged finally resulting in the dielectric failure. It becomes more and more important to recognize the degree of aging and the life time of the insulating materials since it is directly concerned with the reliability of the insulation system. In this paper, the life time of the Cross-linked Polyethylene(XLPE), the insulation layer in the 154kV-grade power cable, is expected and calculated using statistical and mathematical methods. The simulated results are compared with experimental ones and the life exponent of the material is obtained.

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A Study on Growthing Process of Electrical Tree According to Crosslinked Temperature Variation in XLPE (가교폴리에틸렌 수지의 가교온도변화에 따른 전기트리의 진전과정에 관한 연구)

  • 김상기;김덕근;임장섭;오무송;김태성
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.173-176
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    • 1999
  • Crosslinked Decree is an important 7actor to determine dielectric property of crosslinked polyethylene(XLPE) used for the insulation material in Power cables. Recently, though it is necessary to investigate electrical properties according to crosslinked degree as a Part of the whose characterization of cable. it is not examined closely. In this study. crosslinked degree of samples were measured according to temperature and holding time of crosslinking. electrical tree characteristics of these characteristics of these samples were analyzed by crosslinked degree and applied temperature that was chanced from normal temperature to operating temperature of power cables. As a result. when the crosslinked degree was low, dielectric properties were decreased and influence of temperature was increased. but the crosslinked degrees were high, initiation voltages of treeing were increased and dielectric properties were improved. It is proved that the optimum crosslinked degree was one of most important factor for aging time and residual lifetime of Power cable.

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A Study on the Flame Retardancy According to the Aging of Power Cables (전력케이블의 경년열화에 따른 난연성에 관한 연구)

  • Lee, Hae-Pyeong;Kim, Hae-Rim;Park, Young-Ju;Song, Sa-Keum
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2010.10a
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    • pp.358-361
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    • 2010
  • 본 연구에서는 공동지하구 내에서 고온다습하고 유해가스 등 밀폐된 환경에서 사용되었던 CV-Cable을 대상으로 예상되는 Cable sheath 열화기간을 사용기간별(G전선 29년, L전선 14년, L전선 10년)로 3단계로 구분하여 콘칼로리미터와 UL 94 분석장비 등을 활용하여 착화시간, 총발열량, 연소속도를 측정함으로써 전력케이블의 경년열화에 따른 난연성을 비교분석하였다.

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A Possible Sunlight Effect on the Aging Characteristics of Silicone Rubber used for Outdoor Insulation (태양광 모의 열화에 의한 옥외용 실리콘 고무의 열화특성에 관한 연구)

  • Lim, C.R.;Lee, J.H.;Kim, J.T.;Koo, J.Y.;Park, W.K.
    • Proceedings of the KIEE Conference
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    • 1998.07d
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    • pp.1276-1278
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    • 1998
  • In this paper, aging characteristics of silicone rubber used for outdoor insulation have been investigated with regards to sunlight effect. For this purpose, silicone rubbers were aged under the artificial sunlight by use of xenon arc lamp(1500W) and various tests were performed such as tracking, breakdown, contact angle, stress, strain. And then, in order to elucidate the changes of material, analysis have been followed as follows; FT-IR, SEM and EDS. Regarding the effect of the sunlight, it was obs that the surface of test samples are severely da with decreased hydrophobicity, tracking resistan breakdown strength.

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A Health Index of Aged Undeground MV Cables in Domestic (경년열화된 지중 MV급 케이블의 Aging Index)

  • KIM, Yong-Hyun;KIM, Su-Hwan;LEE, Seung-Won;LIM, Jang-Seob
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1216-1216
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    • 2015
  • In this study, the author apply the VLF(Very Low Frequency) tan-delta data that has been measured at each office of the KEPCO 2012 to the Weibull distribution which is the statistical analysis as previous studies for the remaining life prediction through the improvement of the sensitivity and reliability of the degradation state assessment of underground distribution power cables. Also, in this paper, UCD(Used Cable Diagnosis) Matrix proposed by KEPCO was applied to the hierarchy of assessment prioritization. it suggests Aging Index for condition assessment and high reliability of proper economic replacement cycle using the weight according to the assessment prioritization.

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Characterization of Insulation Materials for Low Voltage Cables in a Nuclear Power Plant with ${\gamma}$-Ray Irradiation (방사선조사에 따른 원전 저압케이블용 절연재료의 특성분석)

  • 박정기;이우선;한재홍
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.5
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    • pp.397-404
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    • 2001
  • This study describes the effect of γ-ray irradiation on the properties of insulation materials for low voltage cables in a nuclear power plant. The radiation effects were characterized by measuring OIT, FTIR, electrical properties of the irradiated specimens. As a result, they showed the decrease of OIT and the increase of chemical structural defects with the increase of γ-ray amount. Also, the electrical properties such as dielectrical constant, tan $\delta$ and current were changed by aging. These changes may come from the increase of chemical structural defects by $\delta$-ray irradiation.

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A Study on the Thermal Properties of CNT Reinforced Semiconductive Shield Materials for Power Cables (CNT를 첨가한 전력케이블용 반도전 재료의 열적특성에 관한 연구)

  • Yang, Hoon;Kook, Jeong-Ho;Bang, Jeong-Hwan;Park, Dae-Hee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.12
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    • pp.1062-1067
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    • 2007
  • In this paper, we have investigated thermal properties of semiconductive shield materials for power cables. EEA (Ethylene Ethyl Acrylate) was used for base polymer and TGA (Thermal Gravimetric Analysis) and AFM (Atomic Force Microscope) were investigated with various carbon black and CNT (carbon nanotube) contents. When CNT reinforced composites and conventional composite were investigated with TGA, we knew that thermal properties of CNT reinforced composite were better than them of conventional composite. To investigate roughness, we used AFM. Before and after aging, AFM was applied and after aging, roughness was increased. As a result, suitable CNT and CB(carbon black) content is CNT:CB=50:50.

A Study on the Aging Characteristics and Life Diagnosis of Insulating Materials for Power Cable (전력케이블용 절연재료의 열화특성 및 수명진단에 관한 연구)

  • 박홍태;김경석;남창우;이규철
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.12 no.1
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    • pp.11-17
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    • 1999
  • Aging characteristics of the crosslinked polyethylene have been measured after applying electrical, thermal and combined stresses. ICP and FT-IR measurements confirmed diffusion of low molecular weight components such as antioxidant and presence of carbonyl group. Carbonyl group of aged crosslinked polyethylene under combined stress was detected by FT-IR. As deterioration of the crosslinked polyethylene progresses, crystallinity degree and density decrease. Also, dielectric properties have been measured by tan $\delta$ and $\varepsilon$$_{r}$ measurements. The three-parameter Weibull distribution was found to be the best suited among other probabilistic distribution representing the dielectric breakdown strength of aged crosslinked polyethylene. The scale parameter and location parameter decreases as the applied stress increases. The shape parameter increases as the stress increases.s.

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A Study on the Ultraviolet Aging Characteristics of Outdoor Polymeric Insulating Materials (옥외용 고분자 절연재료의 자외선 열화특성 연구)

  • Kim, Yeong-Seong;Jeong, Sun-Ok
    • Korean Journal of Materials Research
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    • v.9 no.4
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    • pp.409-413
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    • 1999
  • Recently, the polymeric insulators have been accepted in several countries for the outdoor high voltage applications. In comparison with the conventional porcelain, polymeric insulators offer various advantages such as light weight, superior vandal resistance and better contamination performance. The outdoor polymeric insulating materials such as silicone rubber, ethylene propylene diene monomer(EPDM), ethylene vinyl acetate(EVA) and epoxy are aged such as silicone rubber, ethylene propylene diene monomer(EPDM), ethylene vinyl acetate(EVA) and epoxy are aged under the various natural environment with the long-term performance in outdoor. In this paper, the effects of UV-under the various natural environment with the long-term performance in outdoor. In this paper, the effects of UV-ray on the surface of silicone rubber were investigated by using the weather-Ometer. The accelerated aging stresses were simulated by UV radiation, high temperature and humidity as well as water spray. These aging characteristics were examined through contact angle measurements, tracking resistance test, FT-IR and SEM/EDS analysis. The experimental results showed that tracking resistance decreases with increase in the UV-ray irradiation period. But the surface of silicone rubber kept hydrophobicity. It is found that the inorganic filler such as)$ Al(OH_3$ improves tracking resistance and the $Tio_2$is very effective in preventing degradation of silicone rubber surface from UV-ray.

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Analysis on Electrical Tree Growth Characteristics in XLPE According to Crosslinked Degree (XLPE의 가교도 분포에 따른 전기트리 진전 특성 분석)

  • Kim, Sang-Ki;Kim, Dcuk-Keun;Lee, Jeong-Bin;Lee, Jin;Kim, Tae-Sung
    • Proceedings of the KIEE Conference
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    • 1998.11c
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    • pp.901-903
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    • 1998
  • Crosslinked Degree is an important factor to determine dielectric property of crosslinked polyethylene(XLPE) used for the insulation material in power cables. Recently, though it is necessary to investigate electrical properties according to crosslinked degree as a part of the whole characterization of cable. it is not examined closely. In this study, crosslinked degree of samples were measured according to temperature and holding time of crosslinking, electrical tree characteristics of these samples were analyzed by crosslinked degree and applied temperature that was changed from normal temperature to operating temperature of power cables. As a result. when the crosslinked degree was low, dielectric properties were decreased and influence of temperature was increased. but the crosslinked degrees were high. initiation voltages of treeing were increased and dielectric properties were improved. It is proved that the optimum. crosslinked degree was one of most important factor for aging time and residual lifetime of power cable.

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