• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.11
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• pp.1157-1163
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• 2009

This paper introduces the lithium ion battery management system for STSAT-3 satellite. The specifications of lithium ion battery unit are proposed to supply power to the satellite and the overall electrical design for lithium ion battery BMS is presented. Furthermore, the test results of battery management system are shown to verify the design.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.2
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• pp.113-120
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• 2019

We have developed 1 kW-class PEMFC-battery hybrid system independently powering to the building, through the process of system design, current load characteristics analysis, power system configuration for demonstration site and performance evaluation. In order to use the fuel cell and battery as the hybrid type, a control technology for the charging/discharging decision and charging speed of the battery is required rather than using fuel cell. Also output power distribution between PEMFC and the battery is a core of energy management technology. It is confirmed that it is possible to supply independently 1kW powering the building to ensure optimal energy management through the power control experiment of the hybrid system.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.4
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• pp.340-345
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• 2016

Railway vehicle battery is supplying the power required for the initial start-up of the train, in the event of a fault in the vehicle, or catenary for supplying emergency power is one of the components are very important. Currently, the railway vehicles such as nickel-cadmium batteries are being used [1,2]. Ni-Cd batteries as a battery installed in the railway vehicles have a strong corrosion resistance is included, The charge-discharge performance is significantly degraded in cold weather, there is a danger of deterioration or explosion. Train accidents have been caused a lot of damage due to rapid deterioration and cracking of the battery and memory due to the effect of Ni-Cd batteries. In order to solve the problems, There is no risk of degradation, deterioration and leakage, cracking and exploding. maintenance is simple and applied measures proposed to apply Lithium Polymer battery of high performance. In addition, the lack of capacity problems identified by testing the different special systems is replaced by a 70Ah lithium-polymer battery is possible without changing the batteries of 50Ah caused by installing additional equipment in existing older trains were applied to the vehicle.

• Journal of Satellite, Information and Communications
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• v.12 no.4
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• pp.95-99
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• 2017

The lifetime of a battery that supplies all the power required by a satellite in the eclipse is directly related to the lifetime of the satellite. Because the lifetime of the battery is influenced by the charging method of the battery, the power control unit that controls the charging of the battery should be designed in consideration of battery life. The battery charging is performed by controlling the charge current in the power control unit generated from the solar cell in the daytime. In order to prevent overcharge of the battery and for considering frequency of eclipse in each season, parameters related battery charging should be designed differently according to the season and to prevent over-current charging and over-voltage charging during charging, charge current is controlled by monitoring battery charge / discharge status, charge current amount, battery voltage, battery capacity, battery temperature and battery cell voltage. In satellite, tapering method is used to control charge current by reflecting each condition. In this paper, design battery charging algorithm of satellite power control unit using tapering charging method. convert the designed algorithm into a code that can be uploaded to satellites and verify the operation through testing in the established satellite environment.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1213-1214
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• 1995

The advantages for using fuel cell instead of storages for powering electric vehicles are as follows : the energy density of fuel cell is greater than that of battery, fuel cell can be recharged much faster than battery. The objectives of this study are to investigate the status of Fuel Cell Vehicle technologies.

• Journal of the Korean Solar Energy Society
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• v.34 no.4
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• pp.123-129
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• 2014

Photovoltaic and fuel cell systems can be used as power source in mobile robots. At this time the photovoltaic system generally generate power in daytime. The starting time of fuel cell is slower than the lithium battery. To compensate for these disadvantages, a battery charge-discharge system is used. Especially the bi-directional converter is used mainly in the charge-discharge method. The controller in a buck converter controls the input voltage of the converter to meet the maximum power point tracking(MPPT) performance. First of all, the simulations of hybrid system for battery charge-discharge system in each step simulated using solar and fuel cell modeling as input source in PSIM. Experiment of the buck and bi-directional converter system is conducted through using photovoltaic/fuel cel simulator(pCube) instead of solar and fuel cell. This hybrid system for battery charge discharge using photovoltaic/fuel cell generates emergency power for the communication system in mobile robot.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.145.1-145.1
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• 2010

현재 운송수단의 주 동력원으로 사용되고 있는 내연기관은 연료로 사용되는 석유로부터 온실가스가 발생하기 때문에 지구 환경악화의 주범으로 작용하기 때문에 교토 의정서에 의해 많은 제재를 받고 있으며, 이 문제를 해결하기 위해서 다양한 종류의 하이브리드 제품으로 대체하고자 하는 연구개발이 세계 각국에서 활발히 진행되고 있다. 한국은 저탄소 녹색성장이라는 기치하에 2012년 까지 2000만대의 자전거 보급과 세계3대 자전거 생산국으로 발전한다는 비전을 제시하여 향후 자전거 산업이 비약적으로 발전할 것으로 예상되고 있다. 이와 같은 비전을 달성하기 위해서는 저가이면서 출력이 크고 수명이 긴 축전지의 개발이 필수적이며, 이와 더불어 축전지의 성능 발휘를 위해서 이것을 제어할 수 있는 battery management system(BMS)의 개발도 같이 이루어져야 한다. 리튬 배터리의 성능이 우수한 것은 익히 알려진 사실이지만, 고가이기 때문에 소비자들의 부담이 적지 아니하다. 따라서 혁신적인 기술이 개발되어 저가의 배터리를 사용하기 전까지는 납축전지도 같이 사용될 것이며, 본 과제에서는 이와 같은 납 축전지의 수명을 연장시킬 수 있는 BMS를 개발하였다.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.535-537
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• 2008

This paper proposes a modularized two-stage charge equalization converter for a series-connected lithium-ion battery string. In this paper, the series-connected battery sting is modularized into M modules, and each module has K cells in series. With this modularization, low voltage stress on the electronic devices can be achieved. A two-stage dc-dc converter with cell selection switches is employed. The first stage dc-dc converter steps down the high bus voltage to about 10 V. The second stage dc-dc converter integrated with selection switches equalizes the cell voltages. A prototype for 88 lithium-ion battery cells is optimally designed and implemented. Experimental results verify that the proposed equalization method has good cell balancing performance showing low voltage stress, small size, and low cost.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.347-349
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• 2007

Charge equalization scheme for HEV lithium-ion battery system is proposed in this paper, where all the primary windings with in parallel bi-directional switches are coupled in series to provide the equalizing energy from the whole battery string to the specific under charged cells. Moreover, to realize minimized size of equalization circuit employing the proposed cell balancing scheme, the optimal power rating design rule according to equalization time and SOC distribution of imbalance is proposed. A prototype of HEV lithium-ion battery system of four cells shows the outstanding charge equalization performance while maintaining greatly reduced size of cell balancing circuit.

• Transactions of the Korean hydrogen and new energy society
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• v.8 no.2
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• pp.79-90
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• 1997

Extensive work has been done on investigating the inner cell pressure characteristics of sealed type Ni-MH battery in which Zr-Ti-Mn-V-Ni alloy is used as anode. The inner cell pressure of this type Ni-MH battery much more increases with the charge/discharge cycling than that of the other type Ni-MH battery where commercialized $AB_5$ type alloy is used as anode. The increase of inner cell pressure in the sealed type Ni/MH battery using Zr-Ti-Mn-V-Ni alloy system is mainly due to the accumulation of oxygen gas during charge/discharge cycling. The accumulation of oxygen gas arises mainly due to the low rate of oxygen recombination on the MH electrode surface during charge/discharge cycling. The difference of oxygen recombination rate between $AB_5$ type electrode and Zr-Ti-Mn-V-Ni electrode is caused by the difference of electrode reaction surface area resulting from different particle size after their activation and the difference of surface catalytic activity for oxygen recombination reaction, respectively. After EIS analysis, it is identified that the surface catalytic activity affects much more dominantly on the oxygen recombination reaction than the reaction surface area does. In order to suppress the inner cell pressure of Ni-MH battery where Zr-Ti-Mn-V-Ni is used as anode, it is suggested that the surface catalytic activity for oxygen recombination should be improved.