• 한국전기전자재료학회논문지
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• 제34권2호
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• pp.136-141
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• 2021

Heating cables, widely used in office buildings, factories, streets and railways, deteriorate in electrical insulation during operation. The insulation deterioration of heating cables leads to electric discharges that can cause electrical fires. With this background, this paper dealt with a condition monitoring technique for heating cables by the analysis of discharge signals to prevent electrical fires. Insulation deterioration was simulated using an arc generator specified in UL1699 under AC operation, and the characteristic and propagation of discharge signals were analyzed on a 100 meter-long heating cable. Discharge signals produced by insulation deterioration were detected as a voltage pulse because they are as small as a few mV and they are attenuated through propagation path. The frequency spectrum of discharge signals mainly existed in the range from 70 kHz to 110 kHz, and the maximum attenuation of the signal was 84.8% at 100 meters away from the discharge point. Based on the experimental results, a monitoring device, which is composed of a high pass filter with the cut-off frequency of 70 kHz, a comparator, a wave shaper and a microprocessor, was designed and fabricated. Also, an algorithm was designed to discriminate the discharge signal in the presence of noise, compared with the pulse repetition period and the number of pulse counts per 100ms. In the experiment, the result showed that the prototype monitoring device could detect and discriminate the discharge signals produced at every discharge point on a heating cable.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1857-1860
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• 1996

In this paper, ozonizer of neon discharge tube type( Neolamp ) by using silent discharge has been designed and manufactured. The discharge and ozone generation characteristics of Neolamp have been studied with variation of turn-on number( N ) of Neolamp, quality( Q ) and shape of external electrode. The discharge voltage is proportional to gap spacing of spiral external electrode( G ) for constant applied volatge. The discharge current is inversely proportional to G for constant applied volatge. The ozone concentration is inversely proportional to Q and G. Also, ozone concentration and generation are proportional to N. The sterilization characteristics of Escherichia coil have been obtained more than 97[%] at $1.30[mg/{\ell}]$ of liquid ozone concentration.

• 한국기계가공학회지
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• 제16권1호
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• pp.149-156
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• 2017

Graphene nanoplatelet (GNP)-reinforced alumina ($Al_2O_3$) is a promising material for micro-partapplications, particularly micro-nozzle shapes, because of its excellent wearresistance. In this study, a $Al_2O_3$/GNPcomposite with 15 vol% graphene nanoplatelets (GNP) was highly densified and fabricated via spark plasma sintering for micro-electrical discharge drilling (Micro-ED drilling) and the wear resistance property of the composite is evaluated via the ball-on-disk method. In addition, the diameter and shape of the micro-electrodes machined by wire electrical discharge grinding (WEDG), block electrical discharge grinding (BEDG), and new linear block moving electrical discharge grinding (LBMEDG) methods are systematically compared and analyzed to observe the micro-hole machining in the micro-ED drilling of the $Al_2O_3$/15vol% GNP composite.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.628-630
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• 2000

Since the concept for the ozone generation using a nonequilibrium electric discharge techniques had been proposed by Siemens, some experimental and theoretical studies on the ozone generation by streamer corona discharge, surface discharge and silent discharge have been performed. In this paper some results on the discharge characteristics of the silent discharge gap with various dielectric materials were reported. Dielectric materials used in this study were pyrex glass, quartz and glass beefs with diameter of 1 mm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.1090-1092
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• 1999

In this paper, multi discharge type ozonizer has been designed and manufactured. The of ozonizer is equipped with three electrodes(central electrode of screw shape, internal electrode and external electrode). This paper describes the following two characteristics: (1) The characteristics of discharge with variation of output voltage of AC H.V source, flow rate of oxygen supplied gas and discharge voltage. (2) The characteristics of ozone generation by varying flow rate and discharge power.

• Journal of Electrical Engineering and Technology
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• 제1권2호
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• pp.257-262
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• 2006

Insulation failure in an electrical utility depends on the continuous stress imposed upon it. Monitoring of the insulation condition is a significant issue for safe operation of the electrical power system. In this paper, comparison of recognition rate variable classification scheme of PD (partial discharge) sources that occur within an electrical utility are studied. To acquire PD data, five defective models are made, that is, air discharge, void discharge and three types of treeinging discharge. Furthermore, these statistical distributions are applied to classify PD sources as the input data for the classification tools. ANFIS shows the highest rate, the value of which is 99% and PCA-LDA and ANFIS are superior to BP in regards to other matters.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.171-172
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• 2007

PDP의 luminous efficacy의 향상을 위해서는 동작가스의 연구가 매우 중요하다. 본 논문에서는 bolsig simulator를 사용하여 여러 비율의 Xe+Kr+Ne 3원가스 시뮬레이션을 통하여 각 가스입자들에 전달되는 이온화에너지, 여기에너지를 조사하였다. 실험에서 short discharge gap과 long discharge gap을 가진 7인치 테스트 패널 2개를 사용하여 가스압력과 Xe+Kr+Ne 혼합비를 변화시켜가며 discharge voltage, luminance, luminous efficacy를 측정하여, 방전특성을 연구하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.207-211
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• 2000

Deep Interests have been paid on the application of non-thermal plasma technique to solve the environmental pollution problems. $CO_2$ is one of the severe pollutants which cause the acid rain and global warming. In this study, in order to improve the conversion efficiency of $CO_2$, the streamer corona discharge plasma and barrier discharge plasma reactors were made, and the conversion characteristics of $CO_2$ by the corona discharge plasma and some discharge characteristics of these discharge chambers are studied experimentally.

• KIEE International Transactions on Electrophysics and Applications
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• 제5C권6호
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• pp.223-227
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• 2005

Insulation failure of traction motor stator coil depends on the continuous stress imposed on it and knowing its insulation condition is an issue of significance for proper safety operation. In this paper, application of the NN (Neural Network) as a scheme of the off-line PD (partial discharge) diagnosis method that occurs at the stator coil of a traction motor was studied. For PD data acquisition, three defective models were made; internal void discharge model, slot discharge model and surface discharge model. PD data for recognition were acquired from a PD detector. Statistical distributions and parameters were calculated to perform recognition between model discharge sources. These statistical distribution parameters are applied to classify PD sources by the NN with a good recognition rate on the discharge sources.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.451-455
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• 1997

The partial discharge has been blown as the chief breakdown of power equipments. The analysis and the recognition is much difficult because the partial discharge signal is very small and has complex aging pattern. Recently, insulation aging diagnosis based on pattern of phase(Ф), partial discharge magnitude(q), number(n) has been very important. Owing to depreciate the reappearance of aging progress at the electrical tree pattern and to be difficult to analyze visually, the study on partial discharge pattern is suggested to normalizing analysis method of partial discharge signals. This parer is purposed on prediction of life-time measurement of cv-cable, on decision of risk degree with normalization and real-time measurement of partial discharge signals for aging diagnosis of cv-cable. As normalizing the aging signals of electrical tree in cv-cable, it is able to confirm risk degree of insulation material with the distribution of Ф-q-n and recognize the process of aging pattern using neural network.