• Title/Summary/Keyword: Electrical insulator

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Analyses of Leakage Current of Transmission Insulator as a Function of Environmental Condition (환경에 따른 송전용 애자의 누설전류 분석)

  • Choi, In-Hyuk;Lee, Dong-Il;Kim, Chan-Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07b
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    • pp.1166-1170
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    • 2004
  • The leakage currents of transmission insulator were investigated as a function of environmental conditions, such as temperature, humidity, and rainfall. The insulators were artificially contaminated with insoluble yellow soil and kaolin which helped salt to stick on the surface of insulator. The insulators contaminated with the grade of B, C, and D were installed in the KoChang Testing Center. The leakage currents were measured and compared with non-contaminated insulators. The results indicated that the most important factor affecting leakage current was humidity. After heavy rain, the artificially contaminated salt was dissolved, resulting in similar characteristics between with and without contamination

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A Study on Electrical Accident of Distributing Cable Termination with Simulated Badness Construction (평가시공불량을 모의한 배전급 케이블 종단부의 전기적 사고 연구)

  • Choi, Jae-Hyeong;Choi, Jin-Wook;Kim, Sang-Hyun;Kim, Young-Seok;Kim, Sun-Gu;Baek, Seung-Myeong
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.11a
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    • pp.465-470
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    • 2008
  • This paper introduces experimental investigates of an electrical accident of the distributing cable termination with simulated badness construction. We prepared two termination kites, one is built-up type, the other is heat contraction type. Also, we manufactured cable termination that have simulated defect by badness construction and measured their insulation characteristics such as ac (35kV, 1min) and impulse (95kV, $1.2{\times}50{\mu}s$) withstand test. The influence of defects such as thickness and the gap between stress-con of housing and semi-conductor on insulating properties of the termination have been studied. The thickness decrease of insulator decreases ac breakdown strength. Dielectric breakdown traces of insulator that is damaged by knife displayed other shape. The gap of between housing and semiconductor deteriorates dielectric strength of insulator seriously.

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The Frequency Characteristics of Electromagnetic Waves and Discharge Phenomena Caused by Polluted Condition of Solide Insulator Surface (고체절연체표면의 오염상태에 따른 방전현상과 방사전자파의 주파수 특성)

  • 김충년;박원주;이광식;이동인;김인식
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.15 no.4
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    • pp.43-50
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    • 2001
  • In this paper, the discharge phenomena and electromagnetic waves caused by discharge with insertion of a solid insulator and flame between sphere-sphere electrodes in air ware investigated. The surface discharge light and patterns of flame generated on a solid insulator surface were observed by using a CCD(Charged Coupled Device) camera. Also, the radiated electromagnetic waves were measured by using a biconical antenna and a spectrum analyzer. The surface discharge light generated on the solid insulator surface was larger and the size of flame was smaller by increasing allied voltages. Also, voltage distortion by voltage drop was strongly revealed when a insulator surface was polluted. When a solid insulator surface was not polluted, the electric field stength of electromagnetic waves was 10∼17[dBuV/m] higher than a polluted solide insulator, and 5∼9[dBuV/m] higher than a polluted solide insulator and flame.

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Effects of Annealing Ambient on the Anti-Pollution and Mechanical Properties of Functional Film Coated on the Ceramic Substrate (세라믹 기판위에 코팅된 기능성 필름의 열처리 분위기에 따른 내오염 및 기계적 특성)

  • Shan, Bowen;Kang, Hyunil;Choi, Won Seok;Joung, Yeun-Ho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.4
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    • pp.215-217
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    • 2016
  • For the improvement of the anti-pollution properties of porcelain electrical insulators, in this study, we have applied the functional film to the surface of insulator. The functional films were coated on the ceramic substrates which components were like the porcelain electrical insulator. The coating material was applied to ceramic substrate by spray coating method and then the film was cured at around $300^{\circ}C$ for 10 minutes with different gas ambient, such as $O_2$, $N_2$, and only vacuum. We have measured the contact angle of the coated surface, and obtained the lowest angle ($8.9^{\circ}$) and a strong hydrophilic property at vacuum condition. The anti-pollution properties were measured, revealing that as the contact angle decreased, the anti-pollution properties improved. The mechanical hardness and adhesion were both excellent regardless of the annealing ambient.

Characteristics of the Solid-core Station Post Insulators for the Reliability Estimation (변전소용 애자의 신뢰성 평가를 위한 특성 분석)

  • Kim, Chan-Young;Song, Il-Keun;Kim, Ju-Yong;Lee, Byung-Sung;Jung, Jong-Wook
    • Proceedings of the KIEE Conference
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    • 2001.11a
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    • pp.149-151
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    • 2001
  • This paper presents the results of characteristics of the solid-core and suspension insulators for the reliability estimation. The various analytic techniques. such as ICP, XRD, SEM, EDS, were applied for the purpose. The alumina content of solid-core insulator was less than that of suspension insulator The cristobolite was crystallized only in solid-core insulator. The average pore size of solid-core insulator was larger than that of suspension insulator. However, the numbers of pore were fewer in the solid-core insulator.

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Development of Inspection Tool for 154kV Live-line Insulator string (154kV 활선 애자련의 불량애자를 검출하는 활선애자 점검기 개발)

  • Lee, Jae-Kyung;Park, Joon-Young;Oh, Ki-Yong;Jo, Byeong-Hak
    • Proceedings of the KIEE Conference
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    • 2008.10b
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    • pp.373-374
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    • 2008
  • To prevent an insulator failure, a new inspection system is presented for 154kV insulator strings. The inspection system detects fault insulators by measuring resistance and voltage of each insulators in the 154kV insulator string. The inspection instrument obtains autonomously insulation resistance and assigned voltage along the insulator string. The insulator inspection instrument is manipulated by two operators. In addition, a set of mechanism is applied to prevent the system from being reset under live-line condition. We confirmed its effectiveness through experiments.

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Impact Damage Characteristics and Assessment of Insulators Due to Hitting Tester (타격시험기에 의한 애자 파손특성과 평가)

  • Shong, Kil-Mok;Kim, Jong-Min;Kim, Young-Seok;Jeon, Yong-Joo
    • Proceedings of the KIEE Conference
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    • 2008.05a
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    • pp.191-192
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    • 2008
  • In this paper, we investigated on the characteristics and assessment of the insulators damaged by hitting tester(ST-100, Sharp-Eng, KOR). It made that an apparatus act on KS C 3801 for the damaged characteristics and assessment of insulators according to external scattering objects. There are selected 255mm glass insulators and 254mm porcelain insulators as the specimen. The hitting angles of the damaged insulator by pendulum weight are at $72^{\circ}$. At these points, velocity of pendulum weight is about 3.04m/sec and the force is 58.16N. At the hitting angle of 26 degrees, glass insulator is diffused the vibration within it but porcelain insulator is not. The inside vibrations of glass insulator and porcelain insulator are as like as two at the hitting angle of 53 degrees. The damaged glass insulator at the hitting angle of 72 degrees hardly is not diffused.

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Development of Extra High Voltage(400kN) Porcelain Insulator for Transmission Lines (765 kV용 400 kN 현수애자 개발)

  • 최인혁;최장현;이동일;최연규
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.8
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    • pp.348-353
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    • 2003
  • This paper was the research of high voltage suspension insulator (400 [kN]) including pottery stone, feldspar, clay and alumina of 17 [wt%]. The slurry was fabricated after ball milling mixed raw materials. Green compacts were made by the extrusion of jiggering method and were sintered at 1300[$^{\circ}C$] for 50 [min.] in the tunnel kiln. The sintered density was reached to 97% of theoretical density, and the bending strength was 1658 [k $g_{f}$/$\textrm{cm}^2$] and hardness and fracture toughness which was measured by ICL( indentation crack length ) method were 1658 (kgf/$\textrm{cm}^2$) and 27.5 [Gpa], respectively. In measurement of tana and insulation break voltage of 400 (kN) porcelain, tan$\delta$ took some numerical value between 17${\times}$10$_{-3}$ and 61${\times}$10$_{-3}$ and insulation break voltage value was 19.9$\pm$1.4 [㎸/mm]. The test was performed to research whether the shape of pin affect a overvoltage break load or not As a consequence, when a pin was designed a pin diameter 51 [mm] with the bottom form of two-step constructed with straight in the suspension insulator, Insulator showed overvoltage break load 52 [ton] of the highest value and reflected a fine characteristic in aged deterioration test which is one of the accelerated aging test. Also it could be confirmed a fine characteristic through performing the test that electrical property of insulator was established correctly in accordance with IEC 60383-1 standards.s.

The Fabrication and Electrical Characteristics of Pentacene TFT using Polyimide and Polyacryl as a Gate Dielectric Layer (Polymide와 Polyacryl을 게이트 절연층으로 이용한 pentacene TFT의 제작과 전기적 특성에 관한 연구)

  • Kim, Yun-Myoung;Kim, Ok-Byoung;Kim, Young-Kwan;Kim, Jung-Soo
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.4
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    • pp.161-168
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    • 2001
  • Organic thin film transitors(TFTs) are of interest for use in broad area electronic applications. For example, in active matrix liquid crystal displays(AMLCDs), organic TFTs would allow the use of inexpensive, light-weight, flexible, and mechanically rugged plastic substrates as an alternative to the glass substrates needed for commonly used hydrogenated amorphous silicon(a-Si:H). Recently pentacene TFTs with carrier field effect, mobility as large as 2 $cm^2V^{-1}s^{-1}$ have been reported for TFTs fabricated on silicon substrates, and it is higher than that of a-Si:H. But these TFTs are fabricated on silicon wafer and $SiO_2$ was used as a gate insulator. $SiO_2$ deposition process requires a high insulator which is polyimide and photo acryl. We investigated trasfer and output characteristics of the thin film transistors having active layer of pentacene. We calculated field effect mobility and on/off ratio from transfer characteristics of pentacene thin film transistor, and measured IR absorption spectrum of polymide used as the gate dielectric layer. It was found that using the photo acryl as a gate insulator, threshold voltage decreased from -12.5 V to -7 V, field effect mobility increased from 0.012 $cm^2V^{-1}s^{-1}$ to 0.039 $cm^2V^{-1}s^{-1}$ , and on/off current ratio increased from $10^5\;to\;10^6$. It seems that TFTs using photo acryl gate insulator is apt to form channel than TFTs using polyimide gate insulator.

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Simulation of Interface Ageing Effect of Suspension Insulator Using ANSYS (ANSYS를 이용한 현수애자의 계면팽창거동에 따른 특성 평가)

  • 우병철;한세원;조한구
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.8
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    • pp.342-347
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    • 2003
  • The suspension insulators are subjected to harsh environment in service for a long time. Long term reliability of the insulators is required for both mechanical and electrical performances. We studied an analysing method to find out a deformation of brittle porcelain with a thermal expansion of simulation analysis and experimental results show that cement volume growths affect severely to b mechanical failure ageing.