• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.486-491
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• 1991

The photovoltaic modules have each maximum power point, which depending on the intensity of sunlight, modules temperature and etc. Cuk converter is used to obtain the maximum charging power from photovoltaic modules to storage batteries. This paper proposed to a new tracking control method by detecting its current and voltage in photovoltaic power generation system controlled by microprocessor, in order to operate at the maximum power point tracking(MPPT) even if the sunlight and the temperature are varied.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.143-146
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• 1991

This paper describes the analysis of a capacitor-driven induction coil-gun employing an equivalent circuit. The system differerntial equations are solved by using Runge-Kutta method. The velocity characteristics of projectile and current building in barrel ciols are studied. From the results, it is shown the optimal capacitance of capacitors, charging voltage and initial position of the projectile can be determined. These results will be used as the basis data for the design of capacitor driven coil-guns.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.7
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• pp.563-566
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• 2009

This paper presents a motor drive IC for automotive applications. The drive IC is dedicated to control and drive external MOSFETs which directly drive 3-phase motor with a high current. In case of driving high-side power switches, the bootstrap topology is widely used. however, it requires three bootstrap diode and three capacitor respectively. And it needs a minimum charging time to maintain high-side voltage. The motor drive IC uses a charge-pump circuit for all three high-side voltage with various protection schemes for automotive applications.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.7
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• pp.937-942
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• 2013

Equivalent series impedance of high-voltage pulsed power capacitor is one of the important electrical characteristics both for users and for capacitor manufacturers because it may have serious effects on the performance of pulse forming circuits. In this paper, definition of equivalent series impedance and factors which generate equivalent series impedance are reviewed. Theoretical analysis for the calculation of equivalent series impedance based on differential measurement method is described and calculation program has been developed. In order to acquire data which are necessary to calculate equivalent series impedance from discharging current waveform, charging-dischargig controller has been manufactured. Measurement results of equivalent series impedance for high voltage pulsed power capacitor have been given.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.4
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• pp.19-26
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• 2002

A chamber enduring 3,000 bars and an electrical high voltage power system have been designed and installed for studying the characteristics of the plasma produced in electro-thermal chemical propulsion system. In order to test the structural characteristics, polyethylene injectors were used which have 4 or 6 mm inner diameter and several lengths from 15 to 70 mm. The capacitors were charged at the voltages of 5.2, 7.3 and 10.4 kV which correspond to 5.58, 11 and 22.3 kJ in charging energy. The observed resistivities of the plasma injector are close to those predicted by a theoretical model that describes the plasma resistivity according to high current density.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2019-2020
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• 2011

Electric Vehicle Supply Equipment(EVSE) is a system or an equipment to supply electric power for charging the traction batteries on the electric vehicle. Control Pilot is an electric signal generated by EVSE and is transmitted to the electric vehicle by a vehicle coupler and a contact. The duty cycle of control pilot determines the maximum current to be drawn by electric vehicle. When the duty cycle is 5%, it is indicated that digital communication is needed. This paper deals with the data format and definition about communication scheduling through the inband signal on the control pilot of EVSE.

• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.111-112
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• 2017

This paper presents a novel three-port converter for the OnBoard Charger of Electric Vehicles by using an impedance control network. The proposed concept is suitable for charging a main battery and an auxiliary battery of an electric vehicle at the same time due to its power handling capability of the converter without additional switches. The power flow is managed by the phase angle (${\Theta}$) between the ports whereas voltage at each port is controlled by the asymmetric duty cycle and the phase shift (${\Phi}$) between the inverter lags controlled by the impedance control network. The proposed system has a capability of achieving zero voltage switching (ZVS) and zero current switching (ZCS) at all the switches over the wide range of input voltage, output voltage and output power. The feasibility of the proposed system is verified by the PSIM simulation.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.126-129
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• 2009

In this study, it was aimed to develop the re-use technology of ultra-fine silicon powders, by-products during the current production process of high purity poly-Si feedstock. For this goal, the compacts of the silicon powders were tried to fabricate by CIP (Cold Isostatic Pressing) method using silicon rubber mold without chemical binder materials. The density ratio of the silicon powder compacts reached 74%. In order to simulate the actual handling and charging conditions of feedstock material in casting process, a shaking test was carried out and mass loss measured. Finally, the silicon powder compacts were melted using a cold crucible induction melting method and the purity assessment was conducted by Hall effect measurement.

• Korean System Dynamics Review
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• v.7 no.2
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• pp.149-170
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• 2006

In this paper, an energy-economy-environment dynamic simulation model was developed to using system dynamics methodology. It describes current energy-economy-environment systems and forecasts changes caused by levying of carbon tax. The model is composed of three modules: an energy module, an economic module and an environmental module. Variables are interrelated in each module, and three modules are linked by several linkage variables. Setting up the linkage variables is an important factor for the composition of the model. The simulation result shows a change of the national GDP, usage of energy, and $CO_2$ emissions under levying and reinvestment of carbon tax considering various scenarios for the charging cost.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.87-91
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• 2004

In this paper, the paralleled forward converter, that is generally used as the power supply for the low voltage, high current load, is described. The proposed forward converter for battery charging could be provided the power without failure not only in steady state but also in the transient period by the step load variation or the unexpected faults among the converter modules. Each converter nodule designed is operated alone with the self closed controller for the elevation of stability, performance, reliability, and maintainability. The frequency response of the designed converter module is analyzed, and the stability is confirmed in analytic method. And the experiments of the paralleled battery charger are carried out in steady state, in the step load variation.