• Title/Summary/Keyword: Insulators

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Automatic Measuring Apparatus for Salt and Dust Contamination (염진해 오손도 자동측정장치)

  • 최남호;구경완;이명섭;한상옥;정재기;조성배
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.187-190
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    • 1999
  • To reduce the maintenance expence, and the possibility of electric outage and accident, accurate measurement should be carried. But the classical method has some problems in the aspect of man power, reliability, and expence. In this paper, we propose a new type apparatus, which could detect the degree of contamination on insulators on outdoor insulation system, such as transmission and distribution line insulator and bushing. The new type apparatus consists of Pelltier module, electrode system, and measuring part. At first leakage current detecting method was considered, then with the fault(oxidation of electrode) of that method we should propose a another method. We carried various test to prove the possiblity and reliability of the propoused apparatus. And we get some useful result with laboratory test.

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Leakage Current on Surface of Artificially Polluted Composite Insulators (표면 오손상태에 따른 폴리머 애자 하우징 재료의 누설전류 특성)

  • 김재훈;한상옥;이병성;조성수;박강식
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.648-651
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    • 1999
  • This paper introduces the characteristice of leakage current flowing through surface of polluted composite insulation materials. For recording of aged Polymer insulations, data acquisition system(DAS) was developed. These materials were wetted in NaCl solution(each 0.1 wt%, 0.4 wt%). And we boiled them during 24 hours. We measured the leakage current and weight changing of them, each 5 hours. As a result of this experiment, we could know that the leakage current of acted insulation materials was increased by boiling time.

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The Change of Contamination Performance of Polymeric Insulators for Outdoor Use (Salt fog 내에서 옥외용 고분자 절연물의 내오손 성능 변화)

  • 김정호;문중섭;박용판;김동명;원호상
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.505-508
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    • 1999
  • In this study, weight loss, ESDD, surface conductivity and leakage current were measured at the different saline solutions by salt fog method. The magnitude of leakage current was higher at higher conductivity of 2 S/m saline water, but weight loss ESDD and surface conductivity which are indices of degradation were lower. This is considered that the current includes mainly ohmic component which doesn\`t contribute to surface degradation. In addition, it is shown that FFT could be useful in measuring initial transition from hydrophobic to hydrophilic surface.

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Flashover Failure of Polymer Insulator in Distribution Lines (배전용 폴리머애자의 섬락고장)

  • 한재홍;이병성;김찬영;윤태상
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.767-770
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    • 2000
  • This study was investigated for searching a cause of flashover failure of polymer insulator and preparing countermeasures. Hydrophobicity, microstructure and chemical structural change of polymer weathershed were studied by polymer characterization methods. In addition, the electrical properties such as power frequency dry flashover voltage/impulse voltage tests, contamination characteristics were carried out. The hydrophobicity of polymer weathershed was decreased significantly and cracks were observed on the surface. Also, the electrical characteristics did not satisfy the KEPCO specification. The failed polymer insulators showed the more leakage current than 4 years service-aged ones. From the result, it can be concluded that the flashover failure of polymer insulator was attributed to the surface aging and severe contamination.

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Surface Modification of Glass Fiber for Polymer Insulator by Plasma Surface Treatment (플라즈마 표면처리에 따른 고분자절연재료용 유리섬유의 표면개질)

  • 임경범;이덕출
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.5
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    • pp.206-212
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    • 2003
  • It is hard to expect excellent electrical, mechanical and chemical properties from most of the composite materials presently used as insulators due to insufficient wettability property caused by the difference of interfacial properties between the matrix material and the reinforcer. Therefore, various interfacial coupling agents have been developed to improve the interfacial properties of composite materials. But if the wettable coupling agents are used outdoor for a long time, change in quality takes place in the coupling agents themselves, bringing about deterioration of the properties of the composite materials. In this study, glass surface was treated by plasma to examine the effect of dry interface treatment without coupling agent. It was identified that the optimum parameters for the best wettability of the samples at the time of generation of plasma were oxygen atmosphere, 0.1 torr of system pressure, 100 W of discharge power, and 3 minutes of discharge time. Also, the surface resistance rate and dielectric property were improved.

Microstructural Effects Influencing the Thermal Conductivity of High-Temeprature Insulation Firebricks (고온 단열벽돌의 열전도성에 미치는 미세구조의 영향)

  • 장복기;임재봉
    • Journal of the Korean Ceramic Society
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    • v.27 no.6
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    • pp.729-734
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    • 1990
  • The microstructural dependence of thermal conductivity of a high-alumina (ca. 70%) heat-insulating frebricks(ca. 75%porosity) was investigated under special consideration of the tailored-pore shape effects. Pores different shape could be incorporated into the insulators through pore formers : Styrofoam produces spherical pores while saw dust results in parallel plate pores. Concerning the pore-shape effectiveness of thermal insulation, the specimen with irregular plate pores showed much lower values of heat conductivity than those with spherical pores, the values being 0.31 to 0.38 at $600^{\circ}C$ and 0.35 to 0.47 at 100$0^{\circ}C$, respectively. On the contrary, however, other material properties such as strength and softening temeprature under load were turned out to be better in the case of the spherical pores.

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A Study on Electrical Properties of Insulating Materials for Eco-friendly Distribution Power Cables (I) (친환경 배전급 전력케이블용 절연재료의 전기적 특성에 관한 연구 (I))

  • Lee, June-Ho;Kim, Chul-Ho;Cho, Young-Chul;Lee, Moon-Seok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.3
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    • pp.551-556
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    • 2017
  • The cross-linked polyethylene(XLPE) has been most widely used for the power cable insulating layer because of its outstanding properties such as electrical and mechanical properties. However, XLPE is unrecyclable when disposed after replacement and demolishing because it becomes thermosetting through cross-linked process. Recently, because of growing social awareness of recycling and eco-friendly, there is growing need for the development of recyclable insulating materials that can replace XLPE. Therefore, the purpose of this study is to compare the electrical properties of XLPE and recyclable thermoplastic insulating materials. To this end, we compared and analyzed the electrical properties of XLPE and group N2 through AC breakdown test, accelerated water treeing test and accelerated life test(ALT).

A Study on the Evaluation of Indoor Air Environment in Super High-Rise Dwelling House (都市 超高層 住居建築의 室內空氣環境의 評價에 관한 硏究)

  • Park, Mi-Jin
    • Journal of the Korean Society of Safety
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    • v.17 no.4
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    • pp.119-125
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    • 2002
  • The concept of dwelling space is tend to be changed not only to have reasonable mobility but also to have high quality of indoor air with psychologicaa satisfaction and comfortable. Moreover, recent constructed buildings have a big problem because of exhausted pollution gas and particles from building materials. More serious problem occurs from its high air tightness reducing the ventilation for saving the energy and superior adiabatic insulators to have high heat efficiency. Indoor air quality in super high-rise dwelling house was investigated by measuring pollutants such as $CO_2,=;CO,\;MO_2,\;R_n,\;TSP,\;PM_{10}$, HCHO, Offensive ordor. Subjective evaluation of residential environment is processed for the inhabitants who live in research space by testing environmental load in accordance with environment morphology, exterior environmental factor and post occupancy correlation and influence of attention.

A Study on Characteristics of De-electrification and Discharge of Self-Discharged Electrostatic Reducer (자기방전식제건기에 의한 대전물체의 제전 및 방전특성)

  • 박수덕;이동훈
    • Journal of the Korean Society of Safety
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    • v.10 no.2
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    • pp.72-76
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    • 1995
  • An electrostatic passive neutralizer without HV power source has been used widely to reduce charges on insulators such as running plastic films, papers and cloths, but its elimination characteristics and safely have been hardly investigated in detail. Especially, an operation of the passive neutralizer depends primarily on the charged insulator and the elimination ability does not depend on only the neutralizer, because an electrostatic elimination is caused by corona discharges occurring between the passive neutralizer and charged insulator. From a reason described above, the purpose of this study is to examine experimentally the elimination ability of the passive neutralizer. Experiments were made on the corona discharges between the passive neutralizer and charged insulator running at high velocity in practical field to make clear the setting condition of the passive neutralizer for operating effectively and safely. Results obtained from field experiments are presented in this paper.

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A Study on the Memory Characteristics of MONOS Structure for the Scale-down EEPROM (Scale-down EEPROM을 위한 MONOS 구조의 기억특성에 관한 연굴)

  • 이상배;김주열;이상은;김선주;서광열
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1994.05a
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    • pp.127-129
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    • 1994
  • For scale-down EEPROM, MONOS structures with the different thicknesses of gate insulators, are fabricated and the memory characteristics, such as swtching and retention characteristics are investigated. As a results, the devices with the top oxide of 20A thick were deteriorated in retentivity. However, 11V-programmable voltage for ΔV$\sub$FB/=4V and 10-year data retention were achieved in MONOS structure with the t7p oxide of 50 ${\AA}$ thick and nitride 45${\AA}$thick.

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