• Journal of Power Electronics
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• 제12권1호
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• pp.113-119
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• 2012

This paper describes the design and control of a phase shift full bridge converter with a current doubler, which can be used for the on-board charger for the lead-acid battery of electric forklifts. Unlike the common resistance load, the battery has a large capacitance element and it absorbs the entire converter output ripple current, thereby shortening the battery life and degrading the system efficiency. In this paper a phase shift full bridge converter with a current doubler has been adopted to decrease the output ripple current and the transformer rating of the charger. The charge controller is designed by using the small signal model of the converter, taking into consideration the internal impedance of the battery. The stability and performance of the battery charger is then verified by constant current (CC) and constant voltage (CV) charge experiments using a lead-acid battery bank for an electric forklift.

• 천문학논총
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• 제10권1호
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• pp.67-78
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• 1995

An introduction to the first CCD camera system in Bohyunsan Optica1 Astronomy Observatory(CCD#l) is presented. The CCD camera adopts modular dewar design of IfA(Institute for Astronomy at Hawaii University) and SDSU(San Diego State University) general purpose CCD controller. The user interface is based on IfA design of easy-to-use QUI program running on the NeXT workstation. The characteristics of the CCD#l including Gain, Charge Transfer Efficiency, rms Read-Out Noise, Linearity and Dynamic range is tested and discussed. The CCD#l shows 6.4 electrons RON and gain of 3.49 electrons per ADU, and the optimization resulted in about 27 seconds readout time guaranteeing charge transfer efficiency of 0.99999 for both direction. Linearity test shows that non-linear coefficient is $6{\times}10^{-7}$ in the range of 0 to 30,000 ADU.

• 한국자동차공학회논문집
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• 제15권2호
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• pp.182-186
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• 2007

This paper studied performance characteristics of hybrid automotive to replace existing fossil fuel vehicles. Specially, about power split type HEV that is T-HEV's drive system when a vehicle drives at steady speed, monitored both output of each engine, motor and generator and battery SOC (state of charge) and analyzed performance characteristic of power transmission system and electricity power parts. This study shows those that acquired and analyzed information from signals between HCU and each controller of actual T- vehicle. From this study, it is confirmed that each conditions of EV and HEV drive can be a improvement with respect to the fuel efficiency of vehicles.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.851-854
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• 2004

This paper studies Optical Fiber(OF) - LED illuminated display board system for energy saving. The OF-LED illuminated display board system has PV modules, batteries, and charge & discharge system, and dynamic full color display controller. Both maximum power point tracker (MPPT) and constant current & constant current controls (CCVC) are used In govern the charging system. It can be improve the charging efficiency of battery. The objective of this thesis paper is to build advertisement lighting system with OF-LED in to charge a 12-volts lead acid battery by using a field wired PV array. We saved the maintenance cost and developed of advertisement effectiveness. To verify the proposed OF-LED illuminated display board system for energy saving, the detail simulation and experiment results indicate that operating characteristics are verified by experiment with a laboratory prototype in this paper.

• 전력전자학회논문지
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• 제10권5호
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• pp.428-435
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• 2005

본 논문에서는 연료전지 자동차와 같은 하이브리드 시스템에서 양방향 DC-DC 컨버터에 의한 충${\cdot} $방전 동작시 지령전력을 정확히 제어하여 연료전지의 내구성을 향상시키기 위한 전력제어기를 제안하고자 한다. 또한 연료이용률을 향상시키고 배터리의 SOC를 일정하게 하여 에너지를 효율적으로 사용하기 위한 양방향컨버터의 충${\cdot}$방전 운전 알고리즘을 제안한다.

• 전기학회논문지P
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• 제59권3호
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• pp.288-292
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• 2010

Recently, in energy storage system, the EDLC is paid attention as a new environmentally friendly energy storage element. This capacitor has higher energy density than the electrolytic capacitor. Also, this capacitor has a lot of advantage such as no maintenance, longer life cycle and faster charge-discharge time than the battery system. But the EDLC must have a each charge-discharge controller to effectively control, an energy design method circuit to use effectively energy, and several compensation techniques to control a optimal operating. In this respect, this study suggests major parameters to effectively represent the characteristics of EDLC, the measurement methods of those parameters have been investigated with experiments, and the interpretation about the buck/boost DC/DC converter for the operation of EDLC.

• 전력전자학회논문지
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• 제26권4호
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• pp.249-255
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• 2021

A novel current balancing technique for multichannel light-emitting diode (LED) that uses a series resonance and coupled inductor is proposed in this paper. The proposed LED driver balances output currents through frequency control and enables zero-voltage switching. The proposed converter utilizes the charge balance condition of the resonant capacitor and the current sharing function of the coupled inductor to achieve whole LED current balancing without an additional controller. The proposed coupled inductor can integrate the current balancing function and the resonant inductor, so the power density can be increased by reducing the number of magnetic devices. A 40 W prototype is built to verify the validity of this LED driver, and the experimental results are successfully obtained.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.27.1-27
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• 2001

Reheating furnace is a facility of heating up the billet to desired high temperature in the hot charge rolling process and it consists of 3 zones. Temperature control of reheating furnace is essential for successful rolling performance and high productivity. Mostly, temperature control is carried out using PID controller However, the PID control is not effective due to the nonlinearity of the reheating furnace(i.e, presence of the interference of neighboring zones and slow response of temperature etc.). In this paper, feedback linearization method is applied to obtain a linear model of the reheating furnace. Then, controller is designed using simple predictive control method. The effectiveness of this strategy is shown through simulations.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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• pp.1108-1112
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• 2005

Recently, the fuel charge is accounted for very high in the navigation cost. Therefore Shipowner is tried to find method for reducing oil consumption. ERCS(Energy Reduced Cooling System) is one of the method. The ERCS algorithm operates to decrease a power consumption of main sea water cooling pump through inverter control. We have developed ERCS controller with algorithm. The ERCS controller consists of CPU board, Digital I/O board, A/D board, D/A board and LCD/SW board. We tested with dummy signal to confirm the algorithm working correctly and achieved the good results. Before soon we will test under real condition in the ship and expect to get the result as forecasted.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.43-47
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• 1998

In this paper we present the method that improve alarm security system using the electronic circuits added the emergency lamp by our proposed Algorithms. In conventional method the emergency lamp of warning & alarm system was not executed perfectly its performance because of battery with short life. For improving this problem we, using Peripheral Interface Controller IC, designed the circuit added the emergency lamp for an warning & alarm system and for prevent from stopping the electric current, and compared our proposed method with conventional method. By designing the circuit to stop up over charge we can extend life of battery, use of a stoppage of electric current in emergency and according to the lightness around. Therefore we are very convenient and profitable in our life. In this future we will study the method to lower the cost of architecture for practical utilization.