• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.6
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• pp.244-252
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• 1985

A model is presented to explain charging phenomena into the oxide layer when a metal-oxide-silicon(MOS) capacitor is driven by a large amplitude and high frequency ac signal sufficient to produce avalanche injection in the silicon. During avalanche, minority carriers are injected. It is assumed that some of these minority carriers attain sufficient energy to surmount the potential barrier at the interface, and then inter the oxide. Measurements of C-V curves are made for the MOS capacitor with p-type silicon substrates before and after avalanche injection. This paper studies how charging in the oxide and the interface depends on oxide properties. It is concluded that this charging effect is related to the presence of water in the oxide.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.4
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• pp.265-271
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• 2000

A non-contact battery charger for cellular phone is designed using half-bridge series resonant converter. This converter utilizes series resonance to reduce the undesirable effect of large leakage inductance of the detachable transformer and ZVS operation can reduce switching loss and switching noise. In this paper, analysis and design procedure of half-bridge series resonant converter with detachable transformer is presented. The input voltage is 85VAC∼270VAC, and the output voltage and current is 4.1V and 800mA, respectively. Furthermore, a method of calculating the secondary current of the transformer to control the battery charging current in the constant current charging mode is proposed. The performance of the charger is verified through experiments.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.4
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• pp.322-332
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• 2022

Energy storage capacitors based on dielectric ceramics with superior polarization properties and dielectric constant can provide much higher output power density due to their very fast energy charging/discharging rates, which are particularly suitable for operating pulsed-power devices. For an outstanding energy storage performance of dielectric capacitor, a large recoverable energy density could be derived by introducing a slim polarization-electric field hysteresis loop into dielectric materials by various technical approaches. Many research teams have explored various dielectric capacitor technologies to demonstrate high output power density and ultrafast charging/discharging behavior. This article reviews the recent research progress in high-performance dielectric capacitors for pulsed-power electronic applications.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1800-1803
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• 2002

The pulsed power system was widely making use good of many industrial and environments. The pulse generator generally required for short pulse duration and high peak value was forced to consider its volume and economy. In this paper, this system is designed and fabricated which has a compact size of pulse generator with switched MOSFET. We have studied the removal of rust material using Arc discharging in pulsed power system. It have tested their characteristics by adjusting variable voltage charging and pulse repetition rate. As a result, We can eliminate rust materials with this device.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.6
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• pp.455-463
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• 2022

This study proposes a receiving pad identification coil for wireless charging of electric vehicles. The proposed coil identifies the shape of the receiving pad through magnetic coupling with the receiving pad. Therefore, the shape of the coil is designed to show the different magnetic properties of each receiving pad. The accuracy of this design is verified through finite element method simulation. Furthermore, the operation method of the secondary pad identification circuit is described, and the appropriate magnitude and length of the pulse voltage applied to this circuit for receiving pad identification are derived through simulation. The performance of the proposed identification coil set is verified by the experimental results.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.1
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• pp.20-26
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• 2009

In this paper, the switching mode conversion type pulse charger by fly-back converter method for lead battery of the solar cell generator equipment is proposed. And we propose the control circuit and design method of insulated switching mode convert type pulse charger by fly-back convert method in the lead battery. The proposed system can minimize the current consumption by digital pulse. Also the proposed system can generate the constant 10[KHz] frequency, transmit the signal with main control system in the power control system. And it supervises the state of lead battery using one chip micro processor. The proposed the switching mode conversion type pulse charger by the fly-back converter method can charge fast and stabilize lead battery with nominal value 12[V], 20[AH]. Also we propose the design procedure of the power control circuit for turn ratio of fly-back inductor and determining method of values such as the charging current, bulk current, partial current, over current value and fixed charging voltage. The experiment results for the voltage and current wave for partial, bulk, over and fixed charging period show the good charging effect and performance. And the PCB and internal coupling diagram of the switching mode conversion type pulse charger by fly-back converter method is presented.

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1916-1924
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• 2017

Fossil oil, as the main energy of transportation, is destined to be exhausted. The electrification of transportation is a sustainable solution to the energy crisis, since electric power could be acquired from the inexhaustible sun, wind and water. Among all the problems that hinder the development of Electric Vehicle (EV) industry, charging issue might be the most prominent one. In this paper, the service process of a charging station with Battery Energy Storage System (BESS) is analyzed by means of $Cram{\acute{e}}r$ - Lundberg model which has been intensively utilized in ruin theory. The service quality is proposed in two dimensions: the service efficiency and the service reliability. The arrival rate and State of Charge (SOC) upon arrival are derived from 2009 National Household Travel Survey (NHTS). The simulations are performed to show how the service quality is determined by the system parameters such as the number of servers, the service rate, the initial capacity, the charge rate and the maximum waiting time. At last, the economic analysis of the system is conducted and the best combination of the system parameters are given.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1455-1462
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• 2018

As the interests in eco-friendly energy has increased, the interests in Electric Vehicles(EVs) are increasing as well. Moreover, due to the government's economic support for EVs, penetration level of it has rapidly increased. These sharp increases, however, induce various problems in distribution system, such as voltage/frequency variations, peak demand increasement, demand control, etc. To minimize these possible matters, lots of research have conducted. Nevertheless, most of it assumed extremely important factors, such as numbers and charging patterns of EVs. It inevitably results in errors in their research, and thus make it difficult to prevent the possible matters from EVs. In this paper, therefore, we use actual EVs charging data from KEPCO, and analysis and deduction of it were conducted. The simulations were carried out for four aspect(season, region, purpose).

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.725-730
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• 2008

In this study, we found out charged particle's deposition characteristic by experiments of $0.5{\mu}m$, $1.0{\mu}m$, $3.0{\mu}m$ size particle's concentration decay. We carried out the experiments on charged particle deposition onto the vertical cleanroom wall panel and some other fundamental experiments. The particle deposition mechanism is consist of sedimentation, convection, diffusion, thermophoresis, electrostatic and so on. Particle size determines mainly working deposition mechanism. The charged particle is made with corona discharge that are constituted field charging and diffusion charging. In addition, this combinational mechanism is called combined charging. The type of corona discharge determines quantity of particle electrical charge. In conclusion, we assumed that quantity of particle electrical charge accelerations deposition velocity onto the vertical cleanroom wall panel and proved it. And we figured out particle's deposition characteristic through compared between our experiment's results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.2
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• pp.64-72
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• 2001

In this paper, forward Zero Voltage Switching Multi Resonant Converter(ZVS MRC) for non-contact charging energy transmission is reposed. The forward ZVS MRC is effective in adsorbing parasitic element as well as minimizing the switching loss. That can accommodate very high frequency. So forward ZVC MRC is applied to non-contact charging energy transmission. Used converter has saperatable transformer and synchronous rectifiers. Coupling coefficient(k), leakage inductance, coupling inductance and resonant frequency are observed for the air gap. By using the observed value, this circuit is designed and implemented. This proposed circuit is simulated by the PSPICE and experimented. The voltage stress of a main switch and the output power of the converter are measured. This paper show that is compatible for non-contact charging energy transmission.