• Title/Summary/Keyword: count of discharge

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

  • Pang, Man-Sik;Choi, Jae-Hyeong;Kim, Woo-Jin;Kim, Young-Seok;Kim, Sang-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.5
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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.

Partial discharge properties of insulating materials for UPS (UPS용 절연재료의 부분방전 특성)

  • 이덕진
    • Journal of the Korea Computer Industry Society
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    • v.4 no.12
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    • pp.1013-1020
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    • 2003
  • In this paper, the discharge properties due to time variation were investigated in order to estimate a electrical performance of the insulator for small transformer. AC 10[kVl applied to specimen was converted to $\pm$5[V] and stored to personal computer through A/D converter. A period of applied wave form and discharge values were divided into 64 parts and discharge values generated during 10 seconds were accumulated by phases. As a result, it was confirmed that count of discharge, total discharge and the variation degree of average discharge were decreased as time elapsed.

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

  • Pang, Man-Sik;Kim, Woo-Jin;Kim, Young-Seok;Kim, Sang-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.5
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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.

A Study on the Characteristic of Work Roll texturing for the Temper Rolling (조질압연용 Work roll의 조도가공 특성에 관한 연구)

  • 전태옥;전언찬;김순경
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1993.10a
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    • pp.505-511
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    • 1993
  • The results were obtained with changes according to the surface roughness of work roll and method to make the peak count on the roll in the temper rolling, and factors to affect to the work roll surface in actual rolling machine(ie. Temper mill). Conclusions are as follows. 1. E.D.T(Electro-discharge texturing)roll is more uniform roughness distribution than shot blasted roll and it's life time is two timees longer than that of shot blasted because it has more sine wave roughness. 2. The higher peak count of surface roughness, the more time is necessary to work roll texturing In shot blasting method, Surface roughness is relating to the grit size,impeller speed and hardness of roll material, But is can't control the peak count. 3. In shot blast texturing, Surface roughness of temper rolled strip which is transfered surface roughness of work roll is more ununiform than that of E.D.T roll 4. E.D.T roll has more uniform than the shot blasted roll and has more peak count than that of shot blasted roll. The surface of painted strip to image clarity is superior to that of shot blasted roll because E.D.T roll has more peak count and smooth surface.

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Detection of Acoustic Signal Emitted during Degradation of Lithium Ion Battery (리튬이온전지의 열화손상에 의한 음향방출 신호 검출)

  • Choi, Chan-Yang;Byeon, Jai-Won
    • Journal of the Korean Society for Nondestructive Testing
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    • v.33 no.2
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    • pp.198-204
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    • 2013
  • Acoustic emission(AE) signal was detected during charge and discharge of lithium ion battery to investigate relationships among cumulative count, discharge capacity, and microdamages. AE signal was received during accelerated charge/discharge cycle test of a coin-type commercial battery. A number of AE signals were successfully detected during charge and discharge, respectively. With increasing number of cycle, discharge capacity was decreased and AE cumulative count was observed to increase. Microstructural observation of the decomposed battery after cycle test revealed mechanical damages such as interface delamination and microcracking of the electrodes. These damages were attributed to sources of the detected AE signals. Based on a linear correlation between discharge capacity and cumulative count, feasibility of AE technique for evaluation of battery degradation was suggested.

Evaluation and monitoring of degradation mechanism of Li-ion battery for portable electronic device (휴대전자기기용 저용량 리튬이온 배터리의 충방전 열화 기구 분석 및 모니터링)

  • Byeon, Jai Won
    • Journal of Applied Reliability
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    • v.13 no.2
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    • pp.129-140
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    • 2013
  • As a fundamental experimental study for reliability improvement of lithium ion secondary battery, degradation mechanism was investigated by microscopic observation and acoustic emission monitoring. Microstructural observation of the decomposed battery after cycle test revealed mechanical and chemical damages such as interface delamination, microcrack of the electrodes, and solid electrolyte interphase (SEI). Acoustic emission (AE) signal was detected during charge and discharge of lithium ion battery to investigate relationships among cumulative count, discharge capacity, and microdamages. With increasing number of cycle, discharge capacity was decreased and AE cumulative count was observed to increase. Observed damages were attributed to sources of the detected AE signals.

A Study of Electrical and Optical Method of Safety Standards for diagnosis of Power Facility using UV-IR Camera (UV-IR 카메라를 이용한 전력설비 진단을 위한 전기 및 광학적 안전 기준 설정 연구)

  • Kim, Young-Seok;Kim, Chong-Min;Choi, Myeong-Il;Bang, Sun-Bae;Shong, Kil-Mok;Kwag, Dong-Soon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.4
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    • pp.54-61
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    • 2013
  • UV-IR camera is being used for predictive maintenance of high voltage equipment together with measurement of temperature on localized heat and corona discharge. This paper was suggested the judgement method that is the discharge count, UV image pattern and discharge matching rate to apply the UV-IR camera on power facility. The discharge count method is counted by UV image pixel value. the UV image pattern method is determined by the UV image shape using neural network algorithm method, separated by Sunflower, Jellyfish, Ameba. The UV discharge matching is compare the breakdown the UV image size and measuring UV image size according to distance.

A Study on the Effect of Roughness of Rolling Roll in the Paintabilility of Strip (압연롤의 조도가 박판의 도장성에 미치는 영향에 관한 연구)

  • 김순경
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.7
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    • pp.36-43
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    • 1998
  • Surface roughness of cold rolled steel sheet as well as the coating technique itself is quite important in obtaining high image clarity of electronic products and car outer panels. Especially, surface characteristics of steel sheet have acquired increasing attention from the steel and automotive industries. While the influence of such characteristics on paintability formability and painted surface appearance is important in defining steel surface requirements for automotive industries. Therefore this paper is dedicated primarily to the issue of paint appearance and reviews for improvement of roughness and peak count about the surface of work roll for the actual temper mill. The conclusions were obtained as follows ; 1) Roughness and peak count about the surface of steel sheet is strongly affected by surface condition of work roll. 2) The electro-discharge textured roll has more uniform roughness distribution than shot blasted roll and it's painted appearance of steel sheet has more improvement than that of the shot blasted because it has more harmonic wave roughness, and the higher peak count of surface roughness.

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A Study on the Surface Roughness Variation of Work Roll and Strip at the Temper Rolling (조질압연 가공시 작업롤조도와 판면조도 변화에 관한 연구)

  • 전언찬;김순경
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.2
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    • pp.408-417
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    • 1995
  • A study on the surface roughness variation of work roll and strip at the temper rolling was performed. The results were obtained with changes according to the surface roughness of work roll and method to make the peak count on the roll in the temper rolling, and factors to affect to the work roll surface in actual rolling machine (ie. Temper mill). The results suggests that the electro-discharge textured roll has mere uniform roughness distribution than shot blasted roll and its life time is two times longer than shot blasted because it has more sine wave roughness, and it is possible to control the Rmax. In shot blasting method, Surface roughness is related to the impeller speed, But it can't control the peak count.

A Study on the Electro Discharge Texturing Characteristics of the work Roll for Cold Rolling and Surface Roughgness of Steel Strip (냉간압연용 작업롤의 방전 조도가공 특성과 판 조도에 관한 연구)

  • Kim, Soon-Kyung;Jeon, Eon-Chan;Jun, Tae-ok
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.5
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    • pp.69-76
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    • 1995
  • This paper describes characteristics of EDT(Electro Discharge Texturing) and that the strip surface has influence on the paintability. The pulse mode and the capacitor mode of recently developed EDT method were investigated about the peak shape and the roughness of strip surface. And EDT method compared the above-mentioned contents with the SBT(Shot Blast Texturing) method. The peak count of the pulse mode is more than that of the capacitor mode. But the lower roughness below the Ra 3.2 .mu. m of the strip surface, the texturing time of the pulse mode is longer than the capacitor mode. In SBT method, the peak shape is similar to capacitor mode. But the EDT roll has more uniformity than the SBT roll and has more peak count than that of SBT roll. Therefore, in the painted steel sheet, EDT roll gives better surface of clarity image than the SBT roll.

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