• Journal of Power Electronics
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• 제4권3호
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• pp.188-196
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• 2004

The dielectric barrier discharge is recognized as one of the efficient methods of ultraviolet light generation and ozone production. As well, it is widely utilized for gaseous wastes neutralization and other technological processes in industry. This electrochemical reaction is electrically equivalent to a nonlinear capacitive load that represents some difficulties for designing the power supply. Therefore, a conventional power supply is designed for a drastically simplified model of the load and generally is not optimal. This paper presents a fast simulation approach for the nonlinear capacitive model representation of the dielectric barrier discharge load lamp. The main idea of the proposed method is to use analytical solutions of the differential state equations for the load and find the unknown initial conditions for the steady state by an optimization method. The derived expressions for the analytical solutions are rather complicated, however they greatly reduce the calculation time, which make sense when a deeper analysis is performed. This paper introduces the proposed simulation method and gives some examples of its application such as estimation of the load equivalent parameters and load matching conditions.

• Journal of Electrical Engineering and Technology
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• 제11권2호
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• pp.436-444
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• 2016

Oil-paper insulation of valve-side windings in converter transformers withstand electrical stresses combining with AC, DC and strong harmonic components. This paper presents the physical mechanisms and experimental researches on partial discharge (PD) of oil-paper insulation at pulsating DC voltage. Theoretical analysis showed that the phase-resolved distributions of PDs generated from different insulated models varied as the increase of the applied voltages following a certain rule. Four artificial insulation defect models were designed to generate PD signals at pulsating DC voltages. Theoretical statements and experimental results show that the PD pulses first appear at the maximum value of the applied pulsating DC voltage, and the resolved PD phase distribution became wider as the applied voltage increased. The PD phase-resolved distributions generated from the different discharge models are also different in the phase-resolved distributions and development progress. It implies that the theoretical analysis is suitable for interpretation of PD at pulsating DC voltage.

• 한국환경과학회지
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• 제4권2호
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• pp.169-180
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• 1995

This Daper presents effective simulation of the dispersion of thermal discharge which can be relesed at Boryong power plant. Applied numerical models are finite difference method for hydrodynamic analysis and Masch-model comprised of conditions for ambient current velocity. Application of these models is done in Cheonsu Bay Summing up the results of this study are as follows; 1. It is found that the result for measurements of temperature appears high at southwardly Songdo on flood. The reason is that tidal currents which flowed north direction were accompanied with southwardly dispersed thermal discharge. A minute Particle of thermal Plume has a tendency to dispels inward Deacheon Bay. 2. According to the results of numerical experiment, maximum distance for thermal discharge dispersion appeared 10.8 km at lower part and 8.6 km at upper part with power plant outlet as starting point. 3. Comparative the numerical simulation and Airbone Multispectral Scanner indicated that thermal discharge should be verified separative phenomena. The simulated results were compared with field data set showing good agreement. It is concluded that these model can be simulated well.

• 한국대기환경학회지
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• 제14권4호
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• pp.333-342
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• 1998

Plasma process has great possibilities to remove SOx, NOx simultaneously with high treatment efficiency and is expected to be suitable for small or middle plants. It was accomplished to evaluate SO2, NOx control possibility and achieve basic data to control pollutants by use of Surface Discharge Induced Plasma Chemical Process (SPCP) in this study. O3 generation characteristics by discharge of a plate was proportional to O2 concentration and power consumption and inversely proportional to temperature and humidity, In case of dry air, NOx was highly generated by N2 and O2 in air during the plasma discharge process but it was decreased considerably as H2O was added. SO2 removal efficiency was very high, and removal rate was 170,350 mEA at 30,50 watt respectively in flue gas which is usually contain HIO. NOx removal efficiency was about 57% at 40 watt power consumption with 7.5% humidity. It is estimated that H2O has an important role in reaction mechanism with pollutants according to plasma discharge.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.379-380
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• 2008

Recently, ozone is utilized in various fields and its needs are expanding. In this paper, glass and ceramic plate tyre ozonizer have been fabricated to investigate discharge parameter(input power, flow rate of supplied gas, electrode form, etc.) effect to discharge. And the conditions of discharge parameter have been investigated for optimum ozone generation. Ozone concentration is continuously increased with increasing input power for same discharge space, and ozone yield is also increased until maximum point after that it is saturated. Ozone concentration is inversely proportional to flow rate of supplied gas but ozone generation and ozone vield characteristics are improved.

• 한국조명전기설비학회지:조명전기설비
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• 제13권2호
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• pp.203-203
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• 1999

In this paper, high concentration·yield multi-discharge type ozonizer( MDO ) of new discharge type using superposed silent discharge was designed and manufactured. MDO can be consisted with 3 kind of superposed silent discharge type ozonizer( SDO ) in accordance with power supply method that supplying power, which has 180[°] phase difference, to 3 electrodes and double gap. At the moment discharge characteristics and ozone generation characteristics of each SDO were investigated in accordance with quantify of supplied gas, the number of SDO, and the shapes of each SDO. In result ozone generation characteristics of 17185[ppm] and 783[g/kWh] were obtained, and whorl ozone of 17185[ppm] was in contact with dyeing water waste decolonization characteristics was excellent, so it confirmed that MDO could be used as water environment improvement facility.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1846-1849
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• 2000

Off-line and on-line partial discharges were measured on a 828MVA, 22kV and direct hydrogen-cooled large turbine generator. Partial discharge tests were conducted using digital partial discharge detector(PDD) and turbine generator analyzer(TGA). PDD and TGA showed that off-line partial discharge pattern seems to be very, similar to that found with on-line. Most of the partial discharge is originating with the stator slot in the three phases. As the partial discharge activity is very low, the stator insulation condition of this generator is very good.

• 한국전기전자재료학회논문지
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• 제16권7호
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• pp.634-640
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• 2003

This paper is to be researched into ozone generation character of Bi-Ti-Si type high dielectric yield ceramic catalyst discharge tube. And conditions of basic experiment are the outside diameter of discharge tube : 52 mm, the length of discharge tube : 350 mm, the frequence : 900 Hz, the temperature of cooling water : 25 $^{\circ}C$, quantity of flow : 5, 10, 20 l/min, pressure : 1.2, 1.4, 1.6 atm, and distance of discharge gap : 0.4, 0.6, 0.8 mm. Ozone generation characteristics were measured to consumption power. At quantity of flow : 20 l/min, discharge gap : 0.6 mm, pressure : 1.6, and consumption power : 150 W, Maximum ozone generation efficiency of 175 g/kWh was obtained. Maximum ozone generation efficiency was measured below the flow quantity of 20 l/min at below pressure of 1.6 atm. However, Maximum ozone generation efficiency was measured over the flow quantity of 20 l/min at over pressure of 1.6 atm.

• 한국음향학회지
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• 제21권7호
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• pp.614-623
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• 2002

본 논문에서는 전력설비의 열화로 발생되는 부분방전 음압 검출을 위해 간섭계형 광섬유 센서를 제작하고 방전 음압을 측정하였다. 광섬유 센서는 아크릴과 알루미늄에 광섬유를 수회 감은 맨드릴형으로 선택하였으며, 간섭계는 Sagnac간섭계 및 Mach-Zehnder 간섭계를 선택하여 실험하였다. 피에조 (PZT)를 이용하여 구성된 광섬유 간섭계의 적합성을 확인하였다. 방전 음압 발생장치는 절연유 내에 방전 모의셀을 설치하여 방전 음압을 발생시키고, 광섬유 센서로 방전신호를 검출하였다. 실험결과 Sagnac 간섭계가 Mach-Zehnder간섭계보다 방전 음압을 보다 안정적으로 검출함을 확인하였으며, Sagnac 간섭계 센서가 방전 음압 검출에 적합함을 확인하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.704-707
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• 1999

Partial discharge(PD) in air insulated electric power systems is responsible for considerable power lossesfrom high voltage transmission lines. PD in air often leads to deterioration of insulation by the combined action of the discharge ions bombarding the surface and the action of chemical compounds that are formed by the discharge and may give rise to interference in ommunication systems. PD can indicate incipient failure. Thus understanding and classification of PD in air is very important to discern source of PD. In this paper, we investigated PD in air by using statical method. We classified air discharge with corona, surface discharge and cavity discharge by source of discharge. we used the mean pulse-height phase distribution $H_{qmean}(\psi)$, the max pulse-height phase distribution $H_{qmax}(\psi)$ , the pulse count phase distribution $H_n(\psi)$ and the max pulse height vs. repetition rate $H_{q}(n)$ for analysis PD pattern. We used statistical operators, such as skewness(S+. S-1, kurtosis(K+, K-), mean phase(AP+. AP-), cross-correlation factor(CC) and asymmetry from the distribution.