• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.113-116
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• 2004

In this study, the causes of temporal bright image sticking problem in an AC PDP were investigated. The temporal bright image sticking problem in an ac PDP is observed to be a relatively lower luminance following several minutes on-time at a high gray level compared to that of the ordinary turned-on image area. We focused on the detailed causes of image sticking, which are directly related with the visible emission such as the changes in the characteristics of phosphor, MgO surface and gas dynamics. The experimental results show that the thermal quenching of phosphor and temperature-dependent discharge characteristics change cause the image sticking problem.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2120-2122
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• 1999

$SF_6$ gas has been widely used the gas insulated transmission line, gas insulated transformer and gas insulated substation and Polyester film used as the turn insulation with other material. $SF_6$ gas has been actively studied in domestic and foreign countries. In general, when dielectric surface electric field exceed any electric field strength on air, corona discharge is occurred from the dielectric surface. This paper presents the insulation strength of turn insulation of $SF_6$-PET film studied under application of AC voltage, constitute of the plane to plane with PET Film. The results obtained in experimental are summarized that Partial Discharge Initial Voltage(PDIV) of turn insulation depend on gas pressure, but Breakdown Voltage(BDV) did not depend on gas pressure.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.906-909
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• 2006

The secondary electron emission coefficient $({\gamma})$ of the cathode is an important factor for improving the discharge characteristics of AC-PDPs because of its close relationship to discharge voltage. In AC-PDPs, MgO is most widely used as a surface protective layer. In this experimental, we have investigated the electronic structure of the energy band structure of the MgO layer responsible for the high ${\gamma}$. The MgO layers have been deposited by electron beam evaporation method, where the $O_2$ partial pressures have been varied as 0, $5.2{\times}10^{-5}$ torr, $1.0{\times}10^{-4}$ torr, and $4.1{\times}10^{-4}$ torr, in this experiment. It is noted that work function that is energy gap between surface and first defect level of MgO layer has the lowest value for the highest O2 partial pressure of $4.1^{\ast}10^{-4}$ Torr.

• Journal of Information Display
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• v.1 no.1
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• pp.42-47
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• 2000

The relationship between driving voltage and the amount of wall charge in the address period of surface discharge type AC Plasma Display Panel has been investigated. The amount of wall charge on each electrode is obtained simultaneously from the current profiles after applying only one addressing discharge pulse. The wall charge $Q_y$ on the scan electrode Y is almost the sum of $Q_x$ on the address electrode X and $Q_z$ on the sustain electrode Z. The $Q_y$ increased with the driving voltage regardless of the kind of electrode, whereas the addressing $T_d$ decreased. The $Q_x$ and $Q_y$ are increased considerably by blocking voltage $V_z$, whereas $Q_x$ is decreased. The $V_z$ dependence of $Q_x$ $Q_y$ and ${\varrho}_z$ in addressing discharge was $-13{\times}10^{-2}$ (pc/$V_z$), and $60{\times}10^{-2}$ ($pc/V_z$) and $70{\times}10^{-2}(pc/V_z)$, respectively.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.10
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• pp.97-103
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• 2015

This paper presents the characteristics of partial discharge and radiated electromagnetic waves in the existence of a poor contact for the insulation diagnosis of eco-friendly power equipment. AC surface discharge experiment was conducted to simulate the poor contact between a hive voltage electrode (anode) and a solid insulator in $N_2/O_2$ mixture gas under a non-uniform field. The partial discharge voltage to be measured at 0.3MPa increased with the increase of the poor contact gap and was saturated with the gap. In addition to the partial discharge characteristics, it was verified that the defect of the poor contact can be diagnosed using the radiated electromagnetic waves due to the partial discharge, which measured by a biconical EMC antenna and a spectrum analyzer.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.299-307
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• 2015

Reduction in pollution performance of polymeric insulators, aged due to water absorption stress and thermal stress, is a major threat to the reliable operation of power transmission and distribution system. Formation of partial discharges on the surface of wet polluted insulator plays a major role in determining the life time and pollution performance of outdoor polymeric insulators. However, reports on partial discharge characteristics of water absorption stress aged and thermal aged polymeric insulators are scanty. This paper discusses the pollution performance characteristics of accelerated aged polymeric insulators using the advanced ultra wide band PD signal measurement and analysis. Laboratory experiments on accelerated aged polymeric insulators were carried out as per IEC 60507 under AC voltage, at different humidity and contamination levels using NaCl as a contaminant. PRPD pattern and Time-Frequency map analysis of PD signals were carried out. From the results, it can be speculated that PD analysis is a well suited technique to understand the pollution performance of aged polymeric insulators.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.203-206
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• 2002

In this study, a new driving method is suggested to improve the dark room contrast ratio. The principles of the method are that the reset facing discharges occur between scan and address electrodes instead of surface discharge and that the discharge occurs only for the cells that experienced sustain discharge in preceding sub-field after the first sub-field. The dark room contrast ratio is improved more than 7 times compared with the conventional method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.432-435
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• 1997

In AC PDP, electrodes are covered with dielectric layer and the discharge is formed on the surface of the dielectric layer. MgO protection layer on the dielectric layer in PDP prevents a dielectric layer from sputtering and lowers the firing voltage due to a large secondary electron emission yield( ${\gamma}$ ). Until now, the MgO protection layer is mainly prepared by E-beam evaporation. However, there are some problems that is easy pollution and change of its characteristics with time and delamination. Therefore, in this study, MgO protection layer is prepared on dielectric layer by reactive R.F. magnetron sputtering with MgO target. Discharge characteristics and secondary electron emission coefficients of PDP are studied as a parameter of preparation conditions. Discharge voltage characteristics of the prepared MgO layer can be stable and improved by the annealing process in vacuum chamber.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.476-477
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• 2007

This paper described the partial discharge (PD) measurement techniques for diagnosing gas-insulated switches in overhead power distribution system. A capacitive voltage probe to detect PD pulse was designed and fixed on the surface of a bushing. We also designed a coupling network to attenuate AC voltage by 270 dB, and a low-noise amplifier having the gain of 40 dB and 500 kHz~20 MHz 3 dB. From the calibration, it was calculated that the sensitivity of the measurement system was 0.94mV/pC. In the application experiment, we could measure a PD pulse of 45 pC.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.3
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• pp.81-85
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• 2003

This paper describes the results of experiments made to examine the behavior of water droplet on the polymer surface and influence of the charge. In this experiment, water droplet was put on the polymer surface in an applied AC electric field and the investigations of its behavior were done with a high-speed video camera. It can be observed that the droplet elongates and vibrates with being pulled towards the positive electrode in a wave synchronism with the frequency of the power source. The volume and conductivity of water droplet are shown to have a marked effect on the mode of discharge development. These behaviors may be caused by the change of electric field of applied AC voltage and induced charges in/on the water droplet.