• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.3
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• pp.227-233
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• 2011

This paper proposes a design and experiment of three phase interleaved dc-dc converter for 5kW battery charger. The charger consists of a three-phase interleaved dc-dc converter, which interfaces batteries and DC link, and a grid connected inverter. Lead-acid battery is modeled in a simple R-C model by matlab. Parameters of the battery are estimated based on step current discharging test. The battery is connected to three-phase interleaved DC-DC converter in order to reduce the ripple current to the battery and so, increase the lifetime of battery. Controller for charging and discharging mode is designed and tested in a 5kW charger prototype.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.945_946
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• 2009

This paper describes the development of the rapid battery charger for lead-acid battery. Due to heat which is caused by increased internal resistance during charging, it is difficult to increase charging current for the lead-acid battery. In this paper, the rapid charging algorithm which apply short discharging pulse current during charging procedure is developed and it makes the ion layer, which is generated during charging time, disappeared into electrolyte. The prototype battery charger based on resonant converter is developed for 48V battery charger and test procedure is introduced.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.497-500
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• 1999

고속전철의 보조 전원 장치는 차량에 탑재되므로 소형화, 경량화 및 고신뢰성이 요구된다. 보조전원 장치중 Battery Charge는 고압의 직류전원(670Vdc)을 저압의 직류전원(83Vdc)으로 변환하여 객차(Trailer Car : 50kW) 및 동력차(Power Car : 10Kw)에 필요한 직류전원을 안정되게 공급하고 Battery Charger의 고장 발생 시를 대비해 Battery의 최적 충전상태를 유지해야 한다. 기술개발의 최종 목표는 고효율, 고신뢰성 밧데리 충전기 시스템 개발, EMI 저감, 부피와 무게의 소형경량화, 최적 스위칭 기술 및 회로 개발이다. IGBT에 대해 소프트 스위칭 기법을 사용하여 스위칭 손실 저감 및 소자의 스트레스의 저감으로 전력 변환 장치의 효율 향상과 소자의 신뢰성을 확보하였고, 스위칭 주파수를 높여 변압기나 인덕터등의 자기 소자의 크기를 줄였다. Battery Charger를 단일 모듈로 구성하기 보다 5kW 모듈을 여러개 조합한 다중모듈방법으로 병렬 운전하므로써 입출력 전류리플룰 감소시켰으며 시스템의 안정성과 신뢰성을 높일 수 있었다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.11
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• pp.62-74
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• 2012

This paper proposes a new secondary battery charger/discharger available for zero voltage discharge which is used for test equipments and formation process. The proposed system is a switching type converter, and thus the system is high efficiency and more compact as compared with linear type charger/discharger. Conventional switching type charger/discharger can not discharge secondary batteries to zero voltage because of voltage drops in the switching elements and long distributing line(typically 10m). However, the proposed system is able to discharge the battery to zero voltage in constant current mode regardless of the voltage drops. In this paper, we analyze the proposed charger/discharger and the validity of the system is verified by simulation and experiment.

• 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.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.5
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• pp.479-490
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• 2015

The conventional phase-shifted full-bridge (PSFB) converter with an LC filter has been widely used for high-power applications of over 1.0 kW. However, the PSFB converter cannot obtain optimal power conversion efficiency during the battery charging in electric vehicle (EV) on-board battery charger applications because of its unique drawbacks, such as a large circulating current and very high voltage stress in the rectifier diodes. As a result, the converters with a capacitive filter, such as LLC resonant converters, replace the PSFB converter in the EV chargers. This study analyzes the problems of the PSFB converter for EV on-board charger applications in detail. Moreover, the newest converters based on the conventional PSFB converter are reviewed. On the basis of the reviews, new PSFB converter topologies are proposed for EV charger applications. The new topologies are formed by connecting the rectifier stage in the PSFB converter with the output of an LLC resonant converter in series. Many problems of the conventional PSFB converter for EV charger applications can be solved and the performance can be more improved because of this structure; this idea is confirmed by an experiment consisting of prototype battery chargers under the output voltage range of 250-450 Vdc at 3.3 kW.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.773-776
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• 2002

The battery charger of spacecraft has two different modes of operation respectively. One is the bus voltage regulation mode and the other is the charge current regulation mode. And also the battery discharger provide the power during eclipse mode of spacecraft. In this study, a test model of the battery charger and discharger using hi-directional converter are designed and analyzed. These Battery Charger and Discharger is introduced the modular converter method that can be added the converter modules according to the load variation.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.182-183
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• 2013

In the design of the fuel cell charger, it is important to find out the suitable topology and to design the converter to guarantee the performance of the fuel cell as well as the battery. Most of the chargers developed so far have used step-down converters. However, since the small fuel cell stack can only generate a low voltage, it is required to use the step-up converter to charge the battery. In this paper, a modified non-isolated boost charger topology for the Proton Exchange Membrane Fuel Cell (PEMFC) is proposed to meet the strict ripple requirements for the battery charge and its control method by using PI controller is detailed. The feasibility of the proposed topology and its control method is then verified by the experiments.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.6
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• pp.535-542
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• 2017

This paper proposes a simple 3-level interleaved charger-discharger for the uninterruptible power supply (UPS) with various combinations of battery cells. The proposed converter not only improves charging and discharging efficiency, but also reduces the physical volume and the cost. Furthermore, the converter also offers the capability of the neutral point voltage, so that more stable operation can be obtained. In addition, the proposed converter significantly reduces the ripple current of the battery inductor, thereby providing an expected life extension of the battery. Experimental results for a 300kVA UPS prototype verify the validity of the proposed converter. The proposed charger-discharger is suitable for UPSs and energy storage systems (ESSs) with wide input battery voltage ranges.

• Journal of Electrical Engineering and Technology
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• v.8 no.4
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• pp.951-958
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• 2013

This paper proposes the controller design for a stability improvement of an on-board battery charger. The system is comprised of a power factor correction (PFC) circuit and phase shift full-bridge DC-DC converter. The PFC circuit performs the control of the DC-link voltage and the input power factor. The DC-DC converter regulates the voltage and the current in the battery using the DC-link voltage. This paper proposes the design method of PI controller for the PFC circuit using a small signal model. The analysis and design of a type-three controller for the DC-DC converter is also presented. A simulation and experiment has been performed on the on-board battery charger and their results are presented to verify the validity of the proposed system.