• 제목/요약/키워드: Surface discharge

검색결과 2,020건 처리시간 0.025초

Salt fog 시험에서 silicone rubber에서 발생하는 방전 전류의 특성 (The surface discharge performance of silicone rubber in the Salt fog test)

  • 강성화;박영국;이광우;김완수;이용회
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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    • pp.565-569
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    • 1999
  • In these days, the silicone insulators have been increasingly studied and applied for outdoor insulators because it has superior characteristics than porcelain and glass insulators, which have been used for outdoor insulators. First of all, The excellent performance of the silicone rubber in polluted and wet conditions is attributed to the ability of the material to maintain the hydrophobicity of the surface in the presence of severe contamination and wet conditions. This is because of the presence of low molecular weight mobile fluid in the silicone rubber which diffuses to the surface and to above the contamination layer. But, the leakage current and some surface discharge occurs on surface of the composite polymeric insulation materials when the insulator is used for a long time with severe contaminative condition and it can lead the contamination flashover. So the leakage current and the discharge current are important to estimate the condition of the silicone rubber surface. In this paper, the average leakage current, the relation of surface discharge current and phase angle were study to investigate electrical conduction of silicone rubber surface with the salt fog condition.

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평면형 대기압 유전장벽방전장치의 제작 및 동작특성분석 (Fabrication of Atmospheric Coplanar Dielectric Barrier Discharge and Analysis of its Driving Characteristics)

  • 이기융;김동현;이호준
    • 전기학회논문지
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    • 제63권1호
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    • pp.80-84
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    • 2014
  • The discharge characteristics of Surface Dielectric Barrier Discharge (SDBD) reactor are investigated to find optimal driving condition with adjusting various parameter. When the high voltage with sine wave form is applied to SDBD source, successive pulsed current waveforms are observed owing to multiple ignitions through the long discharge channel and wall charge accumulation on the dielectric surface. The discharge voltage, total charge between dielectrics, mean energy and power are calculated from measured current and voltage according to electrode gap and dielectric thickness. Discharge mode transition from filamentary to diffusive glow is observed for narrow gap and high applied voltage case. However, when the diffusive discharge is occurred with high applied voltage, the actual firing voltage is always lower than that with low driving voltage. The $Si_3N_4$, $MgF_2$, $Al_2O_3$ and $TiO_2$ are considered for dielectric protection and high secondary electron emission coefficient. SDBD with $MgF_2$ shows the lowest breakdown voltage. $MgF_2$ thin film is proposed as a protection layer for low voltage atmospheric dielectric barrier discharge devices.

자외선 카메라 개발을 위한 직류 연면방전 특성 (Characteristics of DC Surface Discharge for the Development of UV Camera)

  • 방만식;최재형;김우진;김영석;김상현
    • 조명전기설비학회논문지
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    • 제25권5호
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    • pp.98-103
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    • 2011
  • Recently, UV(ultra-violet rays) camera has attracted a great deal of interest from the view point of easy judgement in inspections and diagnoses of the safety of power equipment. Especilly, UV camera is applied the inspection of UV with corona discharge. One of the most important and difficult problems is the basic research of filter design, materials and corona discharge. In this paper, we will report on the UV generation, corona pulse count and the polarity effect of positive and negative DC surface discharge in air. Also, corona discharge characteristics are analyzed using prototype UV camera of Korea. UV generation and corona pulse count due to surface discharge in positive needle is higher than that of negative needle.

전자파와 수표면 영상을 이용한 산지하천 홍수유량 및 유속 계측 비교 연구 (Comparison of Flood Discharge and Velocity Measurements in a Mountain Stream Using Electromagnetic Wave and Surface Image)

  • 양성기;김동수;류권규;강명수;정우열;이준호;김용석;유호준
    • 한국환경과학회지
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    • 제21권6호
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    • pp.739-747
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    • 2012
  • Due to the difficulties for measuring flood discharge in the dangerous field conditions, conventional instruments with relatively low accuracy such as float still have been widely utilized for the field survey. It is also limited to use simple stage-discharge relationship for assessment of the flood discharge, since the stage-discharge relationship during the flood becomes complicated loop shape. In recent years, various non-intrusive velocity measurement techniques such as electromagnetic wave or surface images have been developed, which is quite adequate for the flood discharge measurements. However, these new non-intrusive techniques have little tested in the flood condition, though they promised efficiency and accuracy. Throughout the field observations, we evaluated the validity of these techniques by comparing discharge and velocity measurements acquired concurrently during the flood in a mountain stream. As a result, the flood discharge measurements between electromagnetic wave and surface image processing techniques showed high positive relationship, but velocities did not matched very well particularly for the high current speed more 3 m/s. Therefore, it should be noted here that special cares are required when the velocity measurements by those two different techniques are used, for instance, for the validation of the numerical models. In addition, authors assured that, for the more accurate flood discharge measurements, velocity observation as well as stage height is strongly necessary owing that the unsteady flow occurs during the flood.

수표면 방전을 이용한 오존발생특성 (Ozone Generation Characteristic Utilizing a Water Surface Discharge)

  • 김인웅;김찬규;박승록;문재덕
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 C
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    • pp.1763-1765
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    • 2002
  • A silent discharge type ozone generator using a water surface as an electrode has been proposed and investigated experimentally. A water surface has many Taylor cones when the ac voltage is applied on its surface, which increase the discharge surface greatly. In this paper, it was studied about the effect of the water conductivity. As increasing the water conductivity, the amount of generated ozone was increased and the silent discharge on the water surface took place steadily and calmly.

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산소 플라즈마 처리에 의한 반도전성 실리콘 고무 표면의 특성변화 (A Study of the Changes of Surface Properties on Semiconductive-Insulating of Silicone Rubber by Oxygen Plasma Treatment)

  • 이기택;황선묵;홍주일;허창수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 춘계학술대회 논문집
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    • pp.25-28
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    • 2005
  • This paper was investigated the changes of surface properties of high-temperature-vulcanized(HTV) semiconductive silicone rubber due to oxygen plasma discharge. The modifications produced on the silicone surface by oxygen plasma were accessed using x-ray photoelectron spectroscopy(XPS), contact angle and Scanning Electron Microscope(SEM). The results of the chemical analysis showed that C-H bonds were broken due to plasma discharge and Silica-like bonds (SiOx. x=3~4) increased. It is thought that the above changes lead to the increase of surface energy of high-temperature-vulcanized(HTV) semiconductive silicone rubber. The micromorphology of surface and hydrophobicity due to plasma discharge based on our results were discussed.

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대기압 RF DBD 방전으로 개질된 폴리이미드의 표면특성 (Surface Properties of Polyimide Modified with He/O2/NF3 Atmospheric Pressure RF Dielectric Barrier Discharge)

  • 이수빈;김윤기;김정순
    • 한국재료학회지
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    • 제16권9호
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    • pp.543-549
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    • 2006
  • Polyimides (PI) are treated with $He/O_2$ and $He/O_2/NF_3$ atmospheric pressure rf dielectric barrier discharge in order to investigate the roles of $NF_3$ that is one of the PI etching gases. Surface changes are analyzed by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and contact angle measurement. The surface roughness of PI and the ratio of C=O, which is hydrophilic functional group, is more increased by $He/O_2/NF_3$ discharge than by $He/O_2$ discharge. The C=O species on the PI surface is increased up to 30 percent with rf power. The surface roughness of PI is increased from 0.4 to 11 nm with rf power. The water drop contact angles on PI, however, are reduced from $65^{\circ}\;to\;9^{\circ}$ by plasma treatment independently of $NF_3$.

모의된 GIS에서 발생하는 부분방전에 관한 연구 (The Simulated study of different partial discharge sources in GIS)

  • 강대용;오광영;박대희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 E
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    • pp.1737-1739
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    • 1998
  • The paper presents experimental results of Partial Discharge(PD) in Gas Insulated Switchgear(GIS), obtained using a computer-aided PD measurement system. Different discharge sources are simulated and identified. These included internal, interface, surface and protrusion. For internal discharge, it showed symmetrical discharge type between positive and negative cycle. Interface discharge showed smaller number and higher peak than internal discharge but symmetrical discharge as well. For surface discharge, it showed small number and high peak in positive half cycle but large number and low peak in negative half cycle. For protrusion discharge, small number and high peak of discharge were shown only in negative half cycle.

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중첩방전 반응기에 의한 오존의 생성 (Ozone Generation by Superimposing Discharge Reactor)

  • 우인성;황명환;조정국;이영희;목연수
    • 한국안전학회지
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    • 제14권3호
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    • pp.63-68
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    • 1999
  • In this paper, characteristics of ozone generation by using coil and SPCP + DC corona reactor was studied. The ceramic-based surface discharge electrode, which was first invented as a high-efficiency ozonizer, has been used as an experimental plasma chemical reactor.(Surface Induced Plasma Chemical Processing, SPCP.) The electrode, however, has a structural disadvantage that a highly energetic plasma region is localized near the electrode surface, which may make it impossible for higher efficiency to realize. In an attempt to overcome this advantage, we have developed a hybrid reactor which employs a corona discharge unit together with the surface discharge unit. Experimental results suggest that the efficiency of the ozone production rate is improved when positive corona discharge is added.

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부싱에서 발생하는 부분방전 신호를 이용한 패턴분석(1) (Pattern Analysis by Using PD Signal generated in Bushings)

  • 이창준;박지훈;함길호;김혁태;김평중
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 C
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    • pp.1951-1953
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    • 2000
  • Partial Discharge is non-disruptive discharge, which can be discriminated to 3 kinds as firstly, internal discharge which is caused by internal voids inside of insulator, secondly, surface discharge which occurs from the surface of insulator and finally, corona discharge which is from the surface of an electrode. In this thesis, three kinds of defects are artificially made to the inside and the surface of the epoxy resine busing with internal voltage detection sensor, which is practically equipped into SF6 gas insulated switchgear for 22.9kV distribution line, so that discrimination of three kinds of PD signals by means of phi-q-n pattern analysis method was performed.

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