• 한국전기전자재료학회논문지
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• 제16권11호
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• pp.1047-1054
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• 2003

Smart battery pack (SBP) for notebook PCs was developed using a cylindrical-type lithium ion battery. Batteries were connected with three serial and two parallel, the nominal capacity and the maximum load of SBP was 4,000mAh and 4.0A, respectively. The SBP was composed of a protection IC, by which safety of lithium ion batteries is maintained against overcharge, overdischarge and overcurrent, and a smart IC, which calculates the remaining capacity and the remaining run time. In matching test on notebook PC using Battery Mark 4.0, real and smart data of END voltage coincided nearly and LB and LLB signal worked norma]]y. And there were errors of less than 1% between the real and the smart data on the residual capacity in the charge and discharge test.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(2)
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• pp.85-88
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• 2001

This paper suggests an improved switch architecture for the rechargeable battery protection IC. In the existing protection IC, charging and discharging switches composed of the CMOS transistor and the diode are external components. It is difficult to integrate the switches in a CMOS process due to the large chip-size overhead and inevitable parasitic effects. In this paper, we propose a new switch architecture of the MOSFET's 'diode connection' method. The performance and chip-size overhead are proved to be adequate for the fully integrated protection IC.

• 조명전기설비학회논문지
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• 제30권1호
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• pp.21-27
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• 2016

The study concerning about the grid connection of the large-capacity battery energy storage system(BESS) is increasing. However, the protection study which is necessary to maintain the reliability of distribution system has been hardly performed. Therefore, this paper analyzes the effect of reclosing among protection issues in distribution system with BESS and proposes the new relcosing method. To verify the proposed method, the BESS, distribution system, and proposed method are modeled by using EMTP/ATPDraw and the various simulations according to the fault clearing time are performed. The simulation results show that the reclosing in distribution system with BESS is successfully performed by proposed method and the operation of BESS is not affected from reclosing.

• Design & Manufacturing
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• 제17권2호
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• pp.42-46
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• 2023

Currently, fossil resources are depleting rapidly. We are looking for energy to replace fossil fuels. They are trying to use electricity to replace internal combustion locomotives. Secondary battery raw materials and chemical additives are pulverized by the high-speed rotation of the grinding disc of the Classifier Separator Mill. Grinding Disc Assembly requires characteristics to withstand abrasion, corrosion, high-speed rotational force and impact. Domestic and foreign grinding discs were analyzed through abrasion resistance, hardness, bending strength, and tensile adhesion strength tests.

• 한국인터넷방송통신학회논문지
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• 제24권2호
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• pp.133-138
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• 2024

리튬이온 배터리는 높은 에너지 밀도 빠른 충전조건 긴 사이클수명의 특성으로 여러 분야에서 사용되고 있다. 하지만 리튬이온 배터리는 과충전, 과방전, 물리적손상, 고온에서의 사용은 배터리 수명 감소와 보호회로 손상에 의한 화재 및 폭발에 의한 인명피해를 입힐 수 있다. 이러한 배터리의 위험성을 낮추며 배터리 성능을 향상시키기 위해서는 충전 및 방전 과정에서의 특성들을 분석하고 이해하여야 한다. 따라서 본 논문에서는 배터리 충방전기와 시뮬레이터를 활용하여 리튬이온 배터리의 충전 및 방전 특성을 분석하여 과충전 과방전에 따른 배터리 수명 감소와 보호회로 손상에 의한 화재 및 폭발에 의한 인명피해를 줄이고자 한다.

• 융합신호처리학회논문지
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• 제25권1호
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• pp.46-51
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• 2024

드론은 최초 군사용으로 사용되었으나 최근들어 사용범위가 확대됨에 따라 농업, 서비스, 물류, 레져용 등 다양한 산업분야에서 폭넓게 사용되어지고 있는 추세이다. 리튬폴리머 배터리는 경량이면서 효율이 우수하여 드론의 전원공급 장치로 주로 사용되고 있다. 이에따라 드론에 안정적인 전원공급을 위하여 경량이면서 에너지 밀도가 높은 리튬폴리머 배터리의 필요성이 커지게 되었다. 그러나 리튬폴리머 배터리는 과충전, 과방전, 단락 등의 이유로 발화 및 폭발로 이어질 수 있어 반드시 보호회로를 탑제하여 사용해야한다. 보호회로는 리튬폴리머 배터리의 전압을 모니터링하는 제어IC인 보호 IC와 과방전시 스위치 역할을 하는 듀얼 N-channel MOSFET 등으로 구성되어있다. 따라서 본 논문은 배터리 보호 IC와 스위치 역학을 하는 MOSFET의 반도체 Die Chip을 이용하여 원칩 패키지 IC형태로 구현하였다. 원칩 패키지 IC로 구현하면 기존 부품 대비 최소 67%의 절감효과를 갖게된다.

• KEPCO Journal on Electric Power and Energy
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• 제6권2호
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• pp.119-122
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• 2020

With recent ESS (Energy Storage System) fire accident, the fault protection performance is becoming more important. However, there has never been any experiments with the protection performance on the faults in the ESS system level. In this study, the effect of AC ground fault and IGBT (Insulated Gate Bipolar mode Transistor) short-circuit failure on MW class ESS was performed experimentally for the first time in the world. First of all, the effect of the AC single line ground fault on battery was analyzed. Moreover, the transient voltage was investigated as a function of the battery capacity and the power level. Finally, the breaking capability and insulation performance of ESS were examined under PCS short-circuit fault condition. Through the tests, it was found that ESS protection system safely blocked the faulty current regardless of the faults, whereas the electronic parts such as IGBT and MC (Magnetic Contactor) were broken by the fault current. Also, the electrical breakdown in ESS resulted from the transient voltage during the protection process.

• 한국전자통신학회논문지
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• 제15권1호
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• pp.71-78
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• 2020

신재생에너지를 활용한 발전원의 경우, 날씨 등의 영향을 많이 받아 전력 생산량이 원활하지 않을 수 있다. 태양광 및 풍력 발전의 효율성을 높이기 위해 에너지 저장 장치(ESS·Energy Storage System)를 활용한다. ESS는 배터리 보호 시스템과 운영관리, 제어체제가 미흡하거나, 설치상의 부주의 등의 원인으로 인해 화재가 속출하고 있으며, 매우 큰 인명 피해와 경제적 손실로 이어지고 있어 ESS의 안정성 및 배터리 보호 시스템 운영관리 기술이 필수적으로 요구되고 있다. 본 논문에서는 ESS 최적화 및 안정적인 운영을 위한 배터리 잔량 산출 알고리즘과 고장 예측 알고리즘을 제시한다. 제시한 알고리즘은 배터리의 충전 및 방전 수행 시 실시간으로 전류량을 누적하여 정확한 배터리 잔량을 산출하며, 배터리 셀 간의 전압불균형 현상을 이용하여 배터리의 고장 유무를 산출한다. 제시된 알고리즘들은 ESS를 최적의 상태로 운영하는데 필요한 정확한 배터리 잔량과 고장 예측이 가능하다. 따라서 ESS의 배터리의 정확한 상태 정보를 측정하고 신뢰성 있게 모니터링 하여 대형 사고를 미연에 방지할 수 있다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.143.2-143.2
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• 2010

Therefore, with this development assignment we'd like to develop the hybrid system combining 800W DMFC (Direct Methanol Fuel Cell) and 1.6kW of Lithium secondary battery pack which can be applied to the most common small cart. a scooter, to secure the development capability of hundreds of Watts DMFC, the high-capacity Lithium secondary battery pack, the technology of BMS (Battery Management System) and the development technology of hybrid system. DMFC, in fact, has lower energy efficiency than PEMFC (Polymer Electrolyte Membrane Fuel Cell); however, it has several advantages in terms of fuel storage and use. It is pretty easy to be stored and used without any additional colling and heating devices because of its insensitive liquid methanol to temperature. In conclusion, DMFC system is the most suitable device for small mobile vehicles.

• Imaging Science in Dentistry
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• 제42권1호
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• pp.1-4
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• 2012

Purpose : Hand-held dental x-ray system is a self contained x-ray machine designed to perform intraoral radiography with one or two hands. The issue about its usage as general dental radiography is still in dispute. The aim of the present study was to assess the relationship between the amount of battery charge and the tube voltage in different handheld dental x-ray systems. Materials and Methods : Seven hand-held dental x-ray units were used for the study. Tube voltage was measured with Unfors ThinX RAD (Unfors Instruments AB, Billdal, Sweden) for 3 consecutive exposures at the different amount of battery charge of each unit. The average and the deviation percentage of measured kV from indicated kV of each unit were calculated. Results : Tube voltage of only 1 unit was 70 kV (indicated by manufacturer) and those of the others were 60 kV. Tube voltage deviation percentage from the indicated kV at the fully charged battery was from 2.5% to -5.5% and from -0.8% to -10.0% at the lowest charged battery. Conclusion : Tube voltages of all units decreased as the residual amount of the battery charge decreased. It is suggested that the performance test for hand-held x-ray system should be performed for the minimum residual charged battery as well as the full charged one. Persistent battery charging is suggested to maintain the proper tube voltage of the hand-held portable x-ray system.