• 한국안전학회지
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• 제27권1호
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• pp.7-13
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• 2012

This paper describes the diagnosis techniques using UV images taken in the field under energized condition of power equipments in order to figure out and analyze the abnormal states on the terminals of power equipments. To classify the features of the terminals, the counted No. of the corona generated at the terminals is defined. According to the result detected, the No. of corona detected on the power equipments installed inside a building is less than that installed outside a building, and it strongly depends on the environment and installed condition. Thus, the environmental condition needs enhanced, and stable operation by the periodic inspection under energized condition of the power equipments is required. Especially, the event counting technique using UV camera is useful for the power equipments apart more than 20 m to apply, and there can be an error due to the features of the sensing techniques when the distance between the user and the objects is close less than 15 m. Therefore, the experimental result shows that event counting technique is employed in the case of the distance more than 15 m. The electrical safety can be ensured by using the UV detection technique and the criteria.

• 조명전기설비학회논문지
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• 제21권9호
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• pp.57-63
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• 2007

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 154[kV] 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 154[kV] 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.

• 조명전기설비학회논문지
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• 제27권4호
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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.

• 조명전기설비학회논문지
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• 제22권4호
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• pp.147-152
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• 2008

본 논문은 코로나 방전에 의한 자기애자와 폴리머애자의 자외선 발생 특성에 관한 것이다. 자외선 카메라를 이용하여 측정하고, KS C IEC 60060-1(2006)의 전압조건을 준수하여 실험하였다. 결과로서 자기애자에서의 코로나 방전은 애자 접합면에서 가장 취약한 부분에서 시작되었다. 폴리머애자는 취약한 접합면에서 자외선이 발생하였으며, 전원 측에서 나타났다. 이로써 자외선 검출을 통해 절연애자의 취약부분이 쉽게 확인되는 것을 알 수 있었다. 또한, 기존의 초음파 검출기술과 비교하여 열화단계가 정량화될 수 있음을 확인하였다. 이는 신뢰성 있는 데이터를 통해 전력설비의 열화를 판단하는 기준에 활용될 수 있다. 향후 현장진단에 적합한 기술로서 앞으로 많은 연구가 기대된다.

• Current Optics and Photonics
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• 제1권3호
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• pp.196-202
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• 2017

Corona discharge is always a sign of failure processes of high-voltage electrical apparatus, including those utilized in electric railway systems. Solar-blind ultraviolet (UV) cameras are effective tools for corona inspection. In this work, we present an automatic railway corona-discharge detection system based on solar-blind ultraviolet detection. The UV camera, mounted on top of a train, inspects the electrical apparatus, including transmission lines and insulators, along the railway during fast cruising of the train. An algorithm based on the Hough transform is proposed for distinguishing the emitting objects (corona discharge) from the noise. The detection system can report the suspected corona discharge in real time during fast cruises. An experiment was carried out during a routine inspection of railway apparatus in Xinjiang Province, China. Several corona-discharge points were found along the railway. The false-alarm rate was controlled to less than one time per hour during this inspection.

• 한국전기전자재료학회논문지
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• 제24권12호
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• pp.996-1001
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• 2011

A bushing is very important because it must supply the high voltage to the power equipment. Generally, the surface of bushing is contaminated with rain, dust, salt and others. A bushing with contaminations at air are 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 on bushing model with contaminations. Also, UV images of discharge in air are analyzed using prototype UV camera of Korea. These results are studied at both AC and DC voltage under a non-uniform field.

• 전기학회논문지
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• 제64권9호
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• pp.1406-1410
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• 2015

The railway catenary systems consist of a complex structure, electrical and mechanical conditions are exposed to dangerous environment due to current collection between pantograph and catenary systems. These two types of conditions for the catenary systems are critically assessed for management and are becoming increasingly more dependent on reliable inspection system. In this paper, a new measurement system which enables inspection of catenary faults was studied and implemented. The system uses wavelength band of ultraviolet (UV) and IR (Infrared) to measure the insulation of corona and temperature of catenary wire. In order to determine the sensitivity of implemented system, the performance test such as distance detection range of UV camera and temperature resolution of IR camera were conducted, respectively. The field test of development system was also conducted in metro and high-speed line using mobile type UV and IR multi-composited measurement systems.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1372-1373
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• 2008

This study investigated the detection of corona discharge on polymer insulators at 13.2kV. Also, It will be analyzed by variety analyzers such as FT-IR, TA, and so on. It carried out an experiment and an actual measurement about corona detection using a UV-camera. This experiment and inspection would need to respect the above criteria. It was required to verify various experimental conditions and on-site inspection afterwards, but it was believed to minimize the measurement error by data-basing research results in a continuous manner and it was necessary to establish diagnosis technologies and standards in various electrical power facilities.

• 천문학회보
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• 제45권1호
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• pp.69.2-69.2
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• 2020

Korea Astronomy and Space Science Institute (KASI) is developing a coronagraph to measure the coronal electron density, temperature, and speed utilizing spectral change of the K-corona around 400 nm. However, near UV light is more affected by atmospheric effect on the ground than visible light. For the total solar eclipse on July 2 2019, KASI organized an expedition team to test the possibility of the similar measurement scheme in the visible light. The observation site was in Las Flores, San Juan, Argentina. We built an imaging spectrograph using micro lenslet array and grism, named Coronal Integral Field Spectrograph (CorIFS). In addition, images of white light corona, wide field background, and all sky were taken with various camera settings. We present the preliminary results of the expedition.