• Title/Summary/Keyword: deterioration class

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The Properties of Breakdown and Test for Resistance to Cracking of Power Cable for PL Countermeasure (PL법 대응을 위한 전력케이블의 열 충격 및 절연파괴 특성)

  • Kim, Young-Seok;Shong, Kil-Mok;Kim, Sun-Gu
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2007.11a
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    • pp.349-352
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    • 2007
  • It is impossible to database(DB) the patterns of cable events and cause analysis of faulted cable because the product liability(PL) law have been enforced in Korea, since 2002. In additions, simulation and pattern of cable events are needed for DB system under accelerated deterioration. In this paper, we tested for resistance to nicking of cable below the 22.9kV class due to thermal stresses. This method of exam is following IEC 60811-3-1(Common test methods for insulating and sheathing materials of electric cables). First of all, set the cable in the thermal stress instrument, temperature changed from -20 degree to 120 degree. After thermal stress, we observed a surface crack of cable through microscope and carried out AC withstand voltage test.

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The Experimental Verification and Fault Cause Analysis of Breakdown on the 6.6kV class Cable Joint (6.6kV급 케이블 중간접속부의 절연파괴 사고원인 분석과 실험 검증)

  • Kim, Young-Seok;Shong, Kil-Mok;Jung, Jin-Su
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1385_1386
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    • 2009
  • In this paper, we examined the faulted cable joint through the external form analysis, material analysis, experimental verification and it's cause diagnosis system. It was not observed the voild, sharp material from the external form analysis and material variation. From the experimental verification, the thickness decrease of an insulator decreased ac breakdown strength suddenly and the breakdown traces of the insulator that was damaged by knife displayed elliptic shape. Thus, the faulted cable is assumed to accident that become dielectric breakdown by the deterioration of insulation performance that can happen when work.

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A study on the Distance and Frequency Variable Characteristics of Flat Plate Induction Heating Element (평판 유도발열체의 거리·주파수 가변특성에 관한 연구)

  • Woo, Hyoung-Gyun;Shin, Dae-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.6
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    • pp.68-74
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    • 2013
  • Induction-heated system is innovative system which applied IH(Induction Heating) magnetic induction heating generated from induction-heated metallic package and high-frequency power circuit technique for thermal converse technique. In this occurs not burning, so that the working environment and deterioration of products can be improved. This technique is used high frequency inverter. By using high frequency inverter high frequency in the range of kHz can be made with conventional alternative current. In this contribution IGBT module is used for high frequency inverter. In this paper are discussed analysis of characteristics according to the each frequency and produced Flat plate induction heating system using 1.5kW-class half-bridge resonant inverter. In addition, operating characteristics of the system to changes in the distance between the coil and the heater, applications of system are also discussed.

Evaluation of Insulation Diagnostic Test Reliability for Stator Winding of High Voltage Induction Motor (고압유도전동기 절연특성시험의 신뢰도 평가)

  • Lee, Kwang-Ho;Kim, Hyun-Il;Kwak, Hee-Jin;Oh, Bong-Keun
    • Proceedings of the KIEE Conference
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    • 2004.11d
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    • pp.46-49
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    • 2004
  • This test was performed to assess the correlation between insulation diagnostic tests and breakdown voltage strength of the stator winding of 6.6kV class induction motor in insulation deterioration condition which have been in service for 5 years after being installed in 1998. The insulation diagnostic tests include resistance, polarization index(P.I), dissipation factor(${\Delta}tan{\delta}$). maximum partial discharges(Qmax) and AC breakdown test. we evaluated the correlation between insulation diagnostic test and AC breakdown test for stator winding of high voltage induction motor.

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A Study on the Electrical Fan Heater using High Efficiency Induction Heating (고효율 유도가열형 전기온풍기에 관한 연구)

  • Shin, Dae-Chul;Woo, Hyoung-Gyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.3
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    • pp.24-30
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    • 2012
  • A proposed the electrical fan heater using induction heating is innovative system which applied IH(Induction Heating) magnetic induction heating generated from induction-heated metallic package and high-frequency power circuit technique for thermal converse technique. In this occurs not burning, so that the working environment and deterioration of products can be improved. The existing heater that low efficiency by heated resistance or using fossil fuel of coal, diesel, kerosene has problems about burden for high cost price. In this paper are compared efficiency the existing heaters and designed electrical fan heaters using 3[kW]-Class full-bridge resonant inverter. In addition, action analysis and application of system are discussed.

Properties of Thermal Performance on Stator Coil of Traction Motor by Accelerated Test (견인전동기 고정자 코일의 열적 열화특성)

  • Park Hyun-June;Lee Chang-Moo;Lee Han-Min;Jang Dong-Uk
    • Proceedings of the KSR Conference
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    • 2003.10c
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    • pp.606-610
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    • 2003
  • The 200 class insulation system which adopted to traction motor have excellent dielectric strength but weaken to thermal stress therefore deterioration phenomena analysis according to thermal stress is necessary. Accelerated thermal aging tests have been used to determine thermal reliability of stator coils used as traction motor in electric multiple unit. The conventional aging test is carried on according to IEC 60034-18-31 and IEEE Std. 275-1992. Variation in insulation resistance, P.I, capacitance, dielectric loss($tan{\delta}$) and partial discharge are measured during the aging cycle. Sample coils for traction motor were tested by accelerated aging test which composed of heat, vibration and moisture. Reliability and expected life were evaluated on the insulation system for traction motor.

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Evaluation of Insulation Condition for High Voltage Induction Motor (고압유도전동기의 절연상태 평가)

  • Lee, Kwang-Ho;Lim, Jae-Il;Kim, Ki-Won;Jung, Jin-Dal;Lee, Eun-Woong
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.783-785
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    • 2003
  • This test was performed to assess the insulation deterioration condition of the stator winding of 3.3kV class induction motors which have been in service for 15 years after being installed in 1988. The insulation diagnostic tests include resistance, polarization index(P.I). dissipation factor(${\Delta}tan{\delta}$) and maximum partial discharges(Qmax). The results of diagnostic tests were compared to the visual inspection in overhaul.

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A Study on Feature Extraction of Fault Signal for Stator Winding using Epoxy/Mica Coupler (에폭시/마이카 커플러를 이용한 고정자권선 결함신호 특징추출에 관한연구)

  • Park, Jae-Jun;Kim, Hee-Dong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.225-226
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    • 2005
  • In this Study, we have acquired 5-simulation Fault types Signals of high voltage Motor stator winding using epoxy/mica coupler. In order to know stator winding fault type using fault signals, we have performed feature extraction to apply wavelet transform technique. we have obtained skewness and kurtosis as statistical parameters of fault signal pattern from non deterioration state winding. We have know that 5 fault signals types have done an exponential function pattern shape but individually fault a class widely was different each other a signal waveform of pattern.

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Use Impacts on Environmental Deteriorations of and around Trails in Soraksan National Park (설악산 국립공원의 등산로 훼손 및 주연부식생)

  • 이준우;오구균;권태호
    • Korean Journal of Environment and Ecology
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    • v.10 no.2
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    • pp.191-204
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    • 1997
  • Eight major trails of Soraksan National Park were selected to investigate the use impacts on environmental edterioration of trail according to the different amount of use. The entire width, bare width, maximum depth and slope of trail as the trail condition surveyed at the total of 188 points were significantly greater on the more heavily-used trail. Major deterioration types of trail were root-exposure, widening, rock-exposure, divergence in order of frequency. And trail conditions of edteriorated points were significantly different from those of non-deteriorated points. The damaged area more severe than Class 4 on trail reached about 10,864m$^{2}$ in total, and especially about 4,560m$^{2}$ in the section between Huiunkak Shelter-Munomigogae trail. The dominant trees of trail edge vegetation were be Quercus mongolica in upper layer, but in lower lauer Carpinus laxiflora, Lespedeza maximowiczii for valley and Carpinus laxiflora, Ghododendron mucronulatum var. cilatum, Tripterygium regelii for ridge.. Especially coverage and number of individuals was highest on Munomighgae-Taech'ongbong trail of the largest use of amount, and each trail was dissimilar in species composition of lower layer of edge vegetation.

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A Study on the Deteriorations Mechanism of Timeworn Buildings in Seoul (대도시 지역의 노후 건축물의 노후 성상에 관한 연구)

  • Kwon, Ki-Hyuk;Lee, Kyoung-Yong;Yang, Hee-Suk
    • Journal of the Korean Society of Hazard Mitigation
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    • v.2 no.4 s.7
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    • pp.87-95
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    • 2002
  • Because of the gravitation of population toward large cities, a number of buildings have been constructed since 1970's. They have been rapidly deteriorated as time passed by. Therefore the purpose of this paper is to present basic data on private buildings managed by the Seoul Metropolitan Government and to analyse deterioration factors of them as well as interrelation. And then, the results of this paper can be used to establish the policy of managing timeworn buildings. Through this study timeworn masonry buildings occupy the major part of timeworn buildings, which have almost structural instability, especially individual residence. Both structure type and building type have an interrelation with the deterioration grade. The structure grade have an interrelation with occupancy class more than structure type.