• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.169-170
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• 2013

One important test for formation and grading of the lithium-ion battery is to confirm the performance of the battery while discharging battery down to zero volts. In this paper, a novel charge/discharge converter with zero-voltage discharge function is proposed. The proposed converter is able to discharge the battery until the voltage reaches to zero volts. The phase-shifted full bridge method is used to charge the battery and the current-fed push-pull method with bidirectional switches is used for the discharge. The ZVS turn-on is achieved in the charge operation and the ZVS turn-off in the discharge operation. The performance of the system is verified by the experiments using lithium-ion batteries.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.539-540
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• 2006

In this paper, We examine that characteristics of formative electret with polymer film and electric charge storage using grid corona discharge. compound polymer of fluorine resin used for material in electret because of high electric charge accumulation, excellent electrical and physical characteristic. All experiments were carried out with circular samples of $Teflon^(R)FEP$ film, 12.5[${\mu}m$] thick. As experiment variables, we used voltage, electrode thickness, discharge electrode gap, and discharge time. According to this variables, we studied on characteristics of formative electret and electric charge storage. Additionally we make a comparative study of the result between the grid corona discharge and needle electrode discharge.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.885-892
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• 2017

In this paper, we proposed a novel crowbar circuit for high-speed discharge charge switching to solve discharge charge-time delay of supply voltage in the conventional crowbar circuit. The proposed circuit is designed to increase the charge-speed after high-speed discharge of supply voltage, thereby reducing the time exposed to radiation damage and, the normal operation time of electronic system after passing the pulse radiation. The simulation of the discharge charge-times before the implement of the hardware is conducted using Cadence's pspice tool, and DUT (Device Under Test) board is fabricated in the device level. The comparison measurement of the crowbar circuits is performed on the satellite-electronic device for 24V. As the result, we confirmed the high-speed function of the proposed circuit by improvement of the discharge-speed 96.8% and the charge-speed 27.3% as compared with the conventional circuit.

• Journal of Energy Engineering
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• v.20 no.4
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• pp.278-285
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• 2011

Computational modelling and simulation for the charge-discharge characteristics of Lithium-ion batteries have been carried out. The battery system consists of a simplified 2-dimensional single cell for the modelling, in which the thermal modelling on the charge-discharge characteristics was conducted in the temperature range from 288 K through 318 K by using FEMLAB as an engineering PDE solver. While material parameters adopted in the present modelling were dependent on the system temperature, their thermal modelling were applied on the simulations of the charge-discharge period and the rate of transferring charges systematically. The resulting simulation shows that the cycle of the charge-discharge shorten itself by reducing the system temperature, regardless of the charge-discharge rates. In addition, the mass-transport phenomena of Lithium ion have been discussed in connection with the charge-discharge characteristics in the battery.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.150-152
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• 2004

The battery charge/discharge process, the final step of the secondary battery production process, requires real-time precision controls for improving both lifetime and performance of the battery cell. In this paper, we present embedded system design for precision control of the secondary battery charge/discharge production process using low power embedded processor based on embedded linux. This system receive charge/discharge command from the main server through ethernet. Compared to existing charge/discharge control system, our design makes low cost and precision control system possible.

• Journal of the Korea Safety Management & Science
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• v.2 no.2
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• pp.187-200
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• 2000

The charge and discharge current in EPR(Ethylene Propylene Rubber), which were irradiated with the radiant capacity of 0~600 ［kgy/h］, have been measured in order to investigate the influence of the atmosphere (oxygen, air and vacuum) on electrical properties. It has been shown that the charge and discharge current increase as the amount of radiant capacity increases in air and vacuum atmosphere. This electrical property degradation can be speculated due to that the C＝O radicals or impurities, which comes from during shaping process, may act as dipoles. On the other hand, the charge and discharge current are shown to be higher in the amount of 1［kgy/h］ than these in 10［kgy/h］ in air atmosphere, because the charge and discharge current can be increased as the exposure time is extended with slower rate. Under the same amount of irradiation, the charge and discharge current in oxygen atmosphere are shown to be higher than those in vacuum. This is possibly due to that the main chain can be broken by oxidation when it is exposed to the $\gamma$ -rays.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.7
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• pp.679-685
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• 2008

This paper describes the degraded properties of between the charge and discharge current for ${\gamma}$-ray irradiated in electric power cable rubbers using in nuclear power generating station. The charge and discharge current of degradation in EPR(Ethylene Propylene Rubber), which were irradiated with the radiant capacity of 0.033 Mrad/h, have been measured in order to investigate the influence of the atmosphere(in amount of reinforcing agent, moisture absorption and heat treatment) on electrical properties. When ${\gamma}$-ray were irradiated on the EPR with more reinforcing agent from 4 to 40 Phr, charge and discharge currents was increase due to the amount of reinforcing agent. It was verified that the discharging and charging currents irradiated by ${\gamma}$-ray were higher than those that was not irradiated. The amount of the degraded current was more after moisture absorption than before moisture absorption. The charge and discharge current after heat treatment was similar to that of before heat treatment and it was decreased with the time elapsed. As these properties related with ${\gamma}$-ray irradiation dose, it is suggested that these properties can be utilized as a index of irradiation degradation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.351-354
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• 2000

AC impedance of LiM $n_2$ $O_4$ and LiM $g_{0.1}$M $n_{1.9}$ $O_4$ samples have been studied at various temperature with charge-discharge test. AC impedance of LiM $n_2$ $O_4$ measured at -2$0^{\circ}C$, room temperature and 5$0^{\circ}C$ revealed that initial impedance before charge-discharge test was gradually decreased and become small by becoming law temperature. It indicates that the Li ion diffusion and the transfer resistance of the cathode are related to the temperature of cycling. Impedance at high temperature was suddenly increased because Mn dissolution and decomposition of electrolyte had been increased during cycling, compared to impedance at low temperature. Therefore, charge-discharge capacity was suddenly decreased at high but was slowly at low. In LiM $g_{0.1}$M $n_{1.9}$ $O_4$, impedance and capacity were stability at room temperature than there at 5$0^{\circ}C$, too. Initial impedance at 5$0^{\circ}C$ before charge-discharge test was small and impedance was suddenly increased during cycling than that at room temperature.ure.ure.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1684-1689
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• 2003

Dielectric Barrier Discharges (DBD) in oxygen and air are well established for the production of large quantities of ozone and are more recently being applied to a wider range of after treatment processes for HAPs(Hazardous Air Pollutants). The potential use as a charger for particle collection are not well known. In this work, we measured charge distribution of nanometer or submicron sized particles passing through the dielectric barrier discharge reactor. The bipolar charge characteristics of particles passing DBD reactor were investigated. Fluorometric method using uranine particles and a fluorometer was employed to examine the bipolar charging characteristics of the charged particles by DBD reactor. Finally, the charge distributions of particles were determined from the electrical mobility classification using DMA.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.1
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• pp.34-39
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• 2015

In this study, the characteristics of partial discharge was measured for the four core silicone cable (0.6/1.0 kV, $1.0SQ{\times}4C$) with insulated part of 15 cm and conductor of 1cm. The following results have been confirmed as a result of this study. When the first line of cable is connected to the positive electrode and the second, third line of cable is connected to the negative electrode, it found that the inception voltage and extinction voltage decreased with increasing the line of negative electrode, and the partial discharge charge quantity(Q) increases, while the number of discharge occurrence has decreased. The inception voltage and extinction voltage of partial discharge has decreased with increasing the degradation rate in the 33%, 67%, 100%. Also, it confirmed that the partial discharge charge quantity(Q) and the number of discharge occurrence has decreased.