• 제목/요약/키워드: Corona

검색결과 1,314건 처리시간 0.03초

방전 침전극의 곡률반경이 이온풍 발생에 미치는 영향 (Effect of Radius of Curvature of a Corona Needle on Ionic Wind Generation)

  • 황덕현;문재덕
    • 전기학회논문지
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    • 제59권3호
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    • pp.604-608
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    • 2010
  • An electric fan for cooling high density electronic devices is limited and operated in very low efficiency. The corona discharge is utilized as the driving mechanism for an ionic gas pump, which allows for air flow control and generation with low noise and no moving parts. These ideal characteristics of ionic pump give rise to variety applications. However, all of these applications would benefit from maximizing the flow velocities and yields of the ionic pump. In this study, a needle-mesh type ionic pump has been investigated by focusing on the radius of curvature of corona needle points elevating the ionic wind velocity and efficiency. It is found that the radius of curvature of the corona discharge needle point influences significantly to produce the ionic wind and efficiency. As a result, an elevated ionic wind velocity and increased ionic wind generation yield can be obtained by optimized the radius of curvature of the corona needle electrode.

정전집진기내의 입자궤적 가시화 (Particle Trajectory Visualization in Electrostatic Precipitator)

  • 박석주;김상수
    • 대한기계학회논문집
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    • 제18권12호
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    • pp.3270-3275
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    • 1994
  • Particle trajectory visualization using laser sheet was performed to investigate the corona wind flow interactions in the one-wire and two-wire type electrostatic precipitators. The corona wind generated by corona discharge was not negligible, and strong flow interactions took place owing to the induced circulatory cells. In the case of one-wire type, as the applied voltage was increased and the cross-section mean velocity was decreased, the effect of corona wind became active. In the case of two-wire type, if upstream discharge voltage was relatively higher than downstream discharge voltage, the effect of upstream corona wind was reduced.

AE센서를 이용한 유중 코로나방전점 위치 및 주파수 영역 검출 (Location and Frequency Domain Detection of Corona Discharge Point in Oil Using AE Sensor)

  • 이상우;김성훈;김인식;김기채;박원주;이광식;이동인
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 1999년도 학술대회논문집-국제 전기방전 및 플라즈마 심포지엄 Proceedings of 1999 KIIEE Annual Conference-International Symposium of Electrical Discharge and Plasma
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    • pp.127-131
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    • 1999
  • In this paper, using a wide-band AE sensor with the frequency range from 100[kHz], the frequency spectra of AE signals generated from the corona discharges of the needle-plane electrode was analyzed to determine the proper ultrasonic sensor. We also examined the relationship between the magnitude of corona discharge and the magnitude of AE signals in peak-to-peak value under the application of 60[Hz] AC high-voltage in oil. From these results, the main frequency spectra of AE signals emitted from the corona discharges of the needle-plane gap were found to be 130[kHz] by the fast fourier transform. The magnitude of AE signals was proportional to the magnitude of corona discharge and discharge current pulse with increasing the applied voltages. Also the detection of corona discharge point location by AE signals was found to be possible by using two sensors.

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Characteristics of a Corona between a Wiring Clamp (Dead End Clamp) and a Porcelain Insulator Used in a 154kV Power Receptacle

  • Han, Woon-Ki
    • International Journal of Safety
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    • 제7권1호
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    • pp.21-25
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    • 2008
  • The occurrence of a corona is that electrical discharge due to the heterogeneity that occurs when an electrical field is concentrated in an electrode due to a cusp formed on said electrode. Wire treatment at the end of a 154kV dead end clamp for end users accelerates the occurrence of corona, which in turn leads to power loss and noise. In this study, the characteristics of the corona which occurs between porcelain insulators and support clamps of overhead lines used in l54kV power receiving facilities for end users were investigated. The corona, which cannot be identified by one common method, was measured utilizing a UV image camera. A risk assessment for fire damage and its status was suggested. The stress distribution of the electrical field by length of bare wire was suggested by means of the finite element method (FEMLAB). As a result, it was found to affect a porcelain insulators. These results can be utilized for the enhancement of clamp installation and safety in power facilities.

장기 코로나 처리에 따른 RTV 실리콘 절연재료의 특성변화 (Effect of Long-term Corona-discharge on RTV Silicone Rubber)

  • 연복희;안종식;허창수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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    • pp.266-269
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    • 2001
  • This paper investigated the aging characteristic under long-term corona discharge on roan temperature vulcanized silicone rubber, which has been using as a protective coating material for solving the contaminant problem. The applied electrical field is 10kV/cm ac and corona discharge treatment was applied on RTV silicone rubber sheet for maximum 250 hours. With the duration of corona discharge. the diffusible low molecular weight species increased, which was determined the usage of n-hexane extraction method. In addition, the contaminant layer was formed on the treated surface, and then measured the contact angle. We investigated the relation of contact angle and diffusible low molecular weight species. It is found that scissor of main chain PDMS and side chains $(CH_3)$ and the generation of LMW species were occurred by a corona discharge. The improvement of hydrophobicity rate is thought due to the increase of diffusible LMW species.

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DC 코로나 방전이 적용된 에틸렌 정상 확산 화염의 Soot 배출 저감 (Reduction of Soot Emitted from a $C_2$$H_4$ Normal Diffusion Flame with Application of DC Corona Discharge)

  • 이재복;황정호
    • 대한기계학회논문집B
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    • 제25권4호
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    • pp.496-506
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    • 2001
  • The effect of corona discharge on soot emission was experimentally investigated. Size and number concentrations of soot aggregates were measured and compared for various voltages. Regardless of the polarity of the applied voltage, the flame length decreased and the tip of flame spreaded with increasing voltage. For the experimental conditions selected, the flame was blown off toward the ground electrode by corona ionic wind. When the negative applied voltage was greater than 3kV(for electrode spacing = 3.5cm), soot particles in inception or growth region were affected by the corona discharge, resulting in the reduction of number concentration. The results show that the ionic wind favored soot oxidation and increased flame temperature. Number concentration and primary particle size greatly increased, when the corona electrodes were located the region of soot nucleation or growth(close to burner mouth).

공기중 코로나방전의 초음파신호 특성 (Ultrasonic Signal Characteristics of Corona Discharges in Air)

  • 이상우;김인식;이광식;이동인;이동헌;배상준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 E
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    • pp.1702-1704
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    • 1998
  • In order to establish the usefulness of ultrasonic techniques for detecting corona discharges in high-voltage power apparatus, it is first necessary to determine the relationship between electrical and ultrasonic signals of corona discharges in air. In this paper, various characteristics of ultrasonic signal detection for point-to-plane corona discharges using a 200[kHz] ultrasonic sensor are examined. In regard to the attenuation and directivity of ultrasonic signals, the signals were inversely proportional to the distance between corona sources and ultrasonic receiving sensors, and half attenuation angles were approximately 7.0 degree. Ultrasonic signals of positive polarities were first obserbed at corona inception voltages. and the signals were increased with increasing the applied voltages.

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오염물질에 따른 변압기부싱 모델의 기중 코로나 방전 특성 (Corona Discharge Characteristics of Transformer Bushing Model with Contaminnations in Air)

  • 방만식;김우진;김영석;김상현
    • 조명전기설비학회논문지
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    • 제26권5호
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    • pp.91-96
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    • 2012
  • The surface of bushing is contaminated with rain, dust, salt and others. A bushing with contaminations in air is serious problem in insulation. Therefore, it is important to understand the inspection and diagnoses of the safety. The ultra-violet rays(UV) camera has attracted interest from the view point of easy judgement. In this paper, we will report on the corona discharge characteristics of surface flashover model with contaminations in air. Also, UV images of discharge and corona pulse count in air are analyzed using prototype UV camera of Korea and a UV sensor with an optic lens. These results are studied at both AC and DC voltage under a non-uniform field.

장기 코로나 처리에 따른 RTV 실리콘 절연재료의 특성변화 (Effect of Long-term Corona-discharge on RTV Silicone Rubber)

  • 연복희;안종식;허창수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집
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    • pp.266-269
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    • 2001
  • This paper investigated the aging characteristic under long-term corona discharge on loon temperature vulcanized silicone rubber, which has been using as a protective coating material for solving the contaminant problem. The applied electrical field is 10kV/cm ac and corona discharge treatment was applied on RTV silicone rubber sheet for maximum 250 hours. With the duration of corona discharge, the diffusible low molecular weight species increased, which was determined the usage of n-hexane extraction method. In addition, the contaminant layer was formed on the treated surface, and then measured the contact angle. We investigated the relation of contact angle and diffusible low molecular weight species. It is found that scissor of main chain PDMS and side chains (CH$_3$) and the generation of LMW species were occurred by a corona discharge. The improvement of hydrophobicity rate is thought due to the increase of diffusible LMW species.

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라미네이팅 필름의 코로나 처리 효과와 주사 전자현미경을 이용한 해석 (The Effect of Corona Treated on Laminating Film and Its Analytical Study by SEM)

  • 김종규;김양평
    • 한국인쇄학회지
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    • 제26권2호
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    • pp.15-30
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    • 2008
  • Studies were carried out the phenomenal observation on the effect of corona treated hotmelt laminating film in process of manufacture by 2 kinds of experiments. These are as follow: 1) In order to verify the treatment reducing value of dynes and dynes durability with the lapse of time, it was checked dynes of a pair of 4 bar discharge electrode with 9 one for 144 hr., and it show results that 9 bar discharge electrode has higher initial dynes as well as keep up 48 dynes durability long than 4 one. 2) Drawn an inference from 3 actions -Chemical-Physical-Mechanical, on laminating film in terms of SEM's observation that are the adhesive status in boundary of corona treated base film, extrusion coating hotmelt layer, and configuration of hotmelt surface after corona treated. In tandem system, EVA layers adhesion keep its stability without corona discharge treatment.

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