• 제목/요약/키워드: Insulation Oil

검색결과 258건 처리시간 0.026초

코어공명을 이용한 허니콤패널의 흡음율 개선에 관한 연구 (A study on the improvement of sound absorption coefficient of an honeycomb panel by the core resonance)

  • 유영훈
    • 동력기계공학회지
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    • 제12권4호
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    • pp.46-51
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    • 2008
  • Honeycomb panel has a constructive advantage because it is constructed with a honeycomb core, so it has relatively higher strength ratio to weight. Therefore honeycomb panel has been used as the light weight panels in the high-speed railway technology and high-speed ship like as cruise yachts. Also it has been used in the aircraft and aerospace industry as a structural panel because light weight structure is indispensible in that field of industry. Recently, the honeycomb panel is embossed in the viewpoints of high oil prices as the lightweight panel of the transport machine, however the sound insulation capacity of the honeycomb panel is poorer than those of uniform and another sandwich panels. In this paper a method to improving the sound absorption coefficient of a honeycomb panel Is studied by using the Helmholtz resonator. The sound absorption coefficients for some kinds of honeycomb cores are demonstrated by the normal incident absorption coefficient method.

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와전류 손실을 적용한 금형으로 제조된 초고압 변압기의 프레스보드의 절연 특성 연구 (A Study on the Insulating Properties of Pressboard for High Voltage Transformer Applied the Mold of Eddy Current Loss)

  • 서왕벽
    • 한국전기전자재료학회논문지
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    • 제28권8호
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    • pp.508-512
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    • 2015
  • Some insulating materials are tested and analyzed with variables to obtain the reliable pressboard which is located to core and coil of high voltage transformer. The high voltage transformer is used in electrical power system and operating reliability. Optimization possibility of pressboard shape including electrical insulation performance could be achieved by analysis simulation. Using insulating pressboard, which is made by mold applied eddy current loss, it could be measured the influences of moisture content for electrical properties. As a result, it is to contribute to improve the performance and ensure the reliability of the pressboard by investigating electrical strength according to the variation oil temperature. In addition pressboard thickness is important design factor to ensure electrical strength in high voltage transformer.

결함별 절연유중 부분방전 측정 연구 (PD Measurement in oil with defects)

  • 선종호;이상화;김광화
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 추계학술대회 논문집 전기설비전문위원
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    • pp.67-69
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    • 2004
  • Since partial discharges in power transformers weaken their insulation performance the detection of partial discharge is very important for prevention of fatal incidents. This study describes use of electromagnetic coupler for measurement of partial discharge of transformers. Spiral antennas of which bandwidth is 0.5GHz to 3GHz were used as coupler and setup in chamber for partial discharge tests. Test results showed that outputamplitudes are increased with PD increase and frequencies of signal measured by these antennas are mostly distributed below about 800MHz.

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변압기 사고 검출을 위한 진동신호 연구 (A Study on the Vibration Signal for Detection of Power Transformer Failure)

  • 김현식;강창구;정찬수;김재철
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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    • pp.493-495
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    • 1995
  • Recently, as power transformer capacity is getting larger, vibration noise of transformer would be large and unexpected failuare of transformer give enormous economic loses, So we aquaire vibration signal, which is maked from transformer windings, core that are airtight out box with in insulation oil, and out box. Also we are fixed rated voltage and changing load current, analyize frequency domain of each vibration signals.

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나노복합체를 이용한 고효율 전기소재 설계 기술 (Properties of Epoxy Based Nanocomposites and their Application to High Efficiency Electric Materials)

  • 이상헌;구경완
    • 전기학회논문지P
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    • 제60권1호
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    • pp.45-47
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    • 2011
  • Recently, research works for electrical properties on the elastic epoxy have been also progressing to diagnose insulation materials by development of measure technology. The epoxy which specially applied for high voltage instruments have required for the electrical, mechanical and thermal properties. Nanocomposites were made from insulating material epoxy resin using for power transformer as varying g amount of addition of SiO2, we found the change of physical characteristics of nanocomposites by using SEM and XRD. To investigate the electrical properties according to the amount of addition and temperature, tested insulting breakdown in silicon oil. As the result of insulting breakdown testing, the insulting breakdown strength increased according to change of the amount of addition.

변압기의 권선변형 검증을 위한 LVI 시험기 개발 (The Development of LVI Tester for WInding Deformation Measurement in Power Transformers)

  • 조국희;김광화;곽희로
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2000년도 학술대회논문집
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    • pp.251-256
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    • 2000
  • The assessment of the condition of a transformer winding which is suspected of having suffered short circuit damage can be difficult. Conventional test such as winding resistance, magnetisation current or insulation resistance will only detect damage if a permanent electrical fault exists. Visual inspection of windings necessitates the removal of oil and in many cases only a very small proportion of the winding can be seen. We describe the characteristics. As the front rise time of recurrent-surge generator pulse less than 1000ns and the peak value of pulse is about 500V, we have the good results of detecting winding deformation in the LVI test of transformers.

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모노폴 안테나에 의한 유중 부분방전의 검출과 분석 (Detection and Analysis of Partial Discharges in Insulation Oil by a Monopole Antenna)

  • 박대원;이정윤;김민수;길경석;천상규
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2011년도 후기공동학술대회 논문집
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    • pp.69-69
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    • 2011
  • 본 논문에서는 유입변압기의 절연진단을 위한 기초연구로 유중 부분방전에 의해 발생하는 전자파의 검출과 분석에 대하여 기술하였다. 유중 방사전자파 측정에는 공진주파수가 1 GHz인 모노폴 안테나를 제작하였다. 절연유 내부에 침-평판 전극계를 설치하고 0~50 kV까지 고전압을 인가시키면서 유중 부분방전의 발생을 모의하였다. 실험결과, 92.3 pC의 부분방전 발생시 1.28 V의 신호가 검출되었다.

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마이크로폰을 이용한 코로나 방전의 측정 및 분석 (Detection and Analysis of Partial Discharges in Insulation Oil by a Monopole Antenna)

  • 조향은;박대원;김민수;길경석;천상규
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2011년도 후기공동학술대회 논문집
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    • pp.68-68
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    • 2011
  • 본 논문에서는 수배전반의 상태진단을 위하여 코로나 방전에 의해 발생하는 음향신호의 측정 및 분석에 대하여 기술하였다. 침-평판 전극계를 제작하여 코로나 방전을 모의하였으며 음향신호의 측정에는 감도 4 mV/Pa, -3 dB의 주파수 대역이 4 Hz~100 kHz인 마이크로폰을 사용하였다. 코로나 방전에 의한 음향신호의 주파수 분석결과, 주파수 성분은 10 kHz~80 kHz에 분포하였으며 20 kHz~40 kHz의 성분이 가장 우세하게 나타났다.

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케이블 접속재료의 전계분포 시뮬레이션 (Electric Field Distribution Simulation of the Cable Joint Materials)

  • 김형주;변두균;신종열;이덕진;이충호;홍진웅
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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    • pp.601-604
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    • 2001
  • The insulation materials of cables used for underground power transmission requires a higher insulating capability. and the most popular method to examine the cable is partial discharge test due to applying variation voltage. In the thesis. air void. silicone oil. of which may possibly exist real cables. are simulated by Electra 2D program. Also the relations between calculated field strength and the void defect type in the cable joint materails. In the modeling. electic field inner to the cable joint material composed by XLPE and EPDM is modeling simulated. We obtained the electric field distribution in void due to two conditions.

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OF 케이블 계통 과도상태 열특성 해석 및 평가 (Analysis and Estimation of the Transient Thermal Characteristics of OF Cable systems)

  • 강지원;이동일;정채균;이종범
    • 대한전기학회논문지:전력기술부문A
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    • 제54권10호
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    • pp.487-495
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    • 2005
  • This paper reviews the characteristic of thermal and temperature of oil field cable in transient state such as grounding fault and lightning surge. For analysis in various conditions, many actual underground power cable systems are modeled using ATP. These results are applied for the examination of temperature increase when the single line to ground fault by the breakdown of insulation part and hitting of lightning surge are occurred. The inner part temperature of OF cable is analysed according to the various kinds of cable using the thermal model of transient state. The temperature increase of sheath and crossbonded lead bv fault current is also analysed using IEC 60949.