• 조명전기설비학회논문지
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• 제26권3호
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• pp.16-23
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• 2012

This paper relates to a study on the economic of electrical storage device for supplying power in sunless days, in the stand alone PV/Wind hybrid system, which it is applied to separate houses. In a photovoltaic/wind hybrid power system used in a separate house, when only the battery is used in sunless days, the capacity of the battery is become larger. For example, as in recent days, if cloudy days are frequent due to anomaly climate, it is difficult to supply power stably by only the battery based upon pre-estimated sunless days. Accordingly, in order to supply stably power of new renewable energy such as solar to any separate houses, it is preferable to reduce the capacity of battery by decreasing the number of sunless days when estimating the capacity of battery and to drive the small generator for compensation of the power shortage.

• 대한전자공학회논문지SD
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• 제48권6호
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• pp.33-38
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• 2011

최근들어 모바일기기의 다기능화 와 고성능화로 인하여, 배터리 사용량이 증가하고 있다. 하지만 필요한 컴퓨팅 파워에 비하여 배터리의 에너지 용량증가의 연구는 더디게 진행되고 있다. 그러므로 본 논문에서는 우리는 배터리 방전특성을 이용하여, 배터리의 사용가능 유효용량을 증가시키는 연구를 하였으며, 무선 전송에서 시스템파워를 끄는 것만으로 배터리 사용시간 연장을 하는 기술을 설명한다. 실험은 표준영상 전송을 통하여 배터리 방전간격에 따른 배터리 사용시간을 측정하고, 사용될 어플리케이션과 발견적 실험을 통하여 배터리 사용시간의 최적화를 달성하였다.

• 전기학회논문지P
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• 제63권2호
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• pp.61-68
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• 2014

Function of battery bank stores energy for DC load in general, and DC power system of the nuclear power plant is used to supply DC loads for safety- featured instrumentation and control such as inverter, class 1E power system control and indication, and station annunciation. Class 1E DC power system must provide a power for the design basis accident conditions, and adequate capacity must be available during loss of AC power and subsequent safe shutdown of the plant. In present, batteries of Class 1E DC power system of the nuclear power plant uses lead-acid batteries. Class 1E batteries of nuclear power plants in Korea are summarized in terms of specification, such as capacity, discharge rate, bank configuration and discharge end voltage, etc. This paper summarizes standards of determining battery size for the nuclear power plant, and analyzes duty cycle for the class 1E DC power system of nuclear power plant. Then, battery cell size is calculated as 2613Ah according to the standard. In addition, this paper analyzes performance test results during past 13 years and shows performance degradation in the battery bank. Performance tests in 2001 and 2005 represent that entire battery cells do not reach the discharge-end voltage. Howeyer, the discharge-end voltage is reached in 14.7% of channel A (17 EA), 13.8% of channel B (16 EA), 5.2% of channel C (6 EA) and 16.4% of channel D (19 EA) at 2011 performance test. Based on the performance test results analysis and size calculation, battery capacity and degradation by age in Korearn nuclear power plant is discussed and would be used for new design.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.359-362
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• 2000

The purpose of this study is to research and develop graphene composite for lithium polymer battery. VO(graphene) composite is one of the promising material as a electrode active material for lithium polymer battery(LPB). We investigated AC impedance response and charge/discharge cycling of VO(graphene)/SPE/Li cells. The first discharge capacity of VO(graphene) cathode with 50wt.% V$_2$O$\sub$5/ was 150mAh/g, while that of VO(graphene) cathode with 85wt.% V$_2$O$\sub$5/ was 248mAh/g. The Ah efficiency was above 98% after the 2nd cycle. The discharge capacity of VO(graphene) anode with 3wt.% V$_2$O$\sub$5/ was 718 and 266mAh/g at cycle 1 and 10 at room temperature, respectively. The VO(graphene) anode with 3wt.% V$_2$O$\sub$5/ in PVDF-PAN-PC-EC-LiC1O$_4$ electrolyte showed good capacity with cycling.

• 한국산업융합학회 논문집
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• 제26권1호
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• pp.27-34
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• 2023

This study conducted a study on a small-capacity PCS using lithium-ion batteries used in personal mobility. Most of the batteries in Personal Mobility only charge with external chargers and are used only as mobile energy sources. However, this paper aims to charge the battery of PM using PV and system power or to use the charged power as a stand-alone power supply. The developed PCS can be operated as a two-channel battery charger/discharger, a battery charger using solar power, and a stand-alone solar inverter depending on the operation method. The validity of the manufactured small-capacity PCS was verified through experiments.

• 한국기계가공학회지
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• 제8권2호
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• pp.90-95
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• 2009

This paper presents a new lithium ion unit-cell and pack battery by using a new formulation ratio of material. The three types of formulation ratio for the unit-cell were used. The life cycle and basic properties of the lithium ion unit-cell$({\Psi}18{\times}65(mm))$ about one of them were acquired by the charge-discharge experiment. The nominal voltage, nominal capacity and cycle life output of the lithium ion unit-cell is respectively 3.7V, 2.4Ah, and above 500cycle. Pack type lithium ion battery has the size of $29.5{\times}73.5{\times}115(mm)$ and the weight of 300g. As the results, the weight and bulk of lithium ion battery used to a safety lamp were decreased to 1/4 and 1/7. In addition, the comparison of the new lithium ion battery and lead storge battery for confirming the effectiveness of the new lithium ion battery have been performed.

• 전기학회논문지P
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• 제65권4호
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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.

• 한국분무공학회지
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• 제22권2호
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• pp.69-79
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• 2017

When designing a redox flow battery system, compression of battery stack is required to prevent leakage of electrolyte and to reduce contact resistance between cell components. In addition, stack compression leads to deformation of the porous carbon electrode, which results in lower porosity and smaller cross-sectional area for electrolyte flow. In this paper, we investigate the effects of electrode compression on the cell performance by applying multi-dimensional, transient model of all-vanadium redox flow battery (VRFB). Simulation result reveals that large compression leads to greater pressure drop throughout the electrodes, which requires large pumping power to circulate electrolyte while lowered ohmic resistance results in better power capability of the battery. Also, cell compression results in imbalance between anolyte and catholyte and convective crossover of vanadium ions through the separator due to large pressure difference between negative and positive electrodes. Although it is predicted that the battery power is quickly improved due to the reduced ohmic resistance, the capacity decay of the battery is accelerated in the long term operation when the battery cell is compressed. Therefore, it is important to optimize the battery performance by taking trade-off between power and capacity when designing VRFB system.

• 한국수소및신에너지학회논문집
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• 제27권6호
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• pp.753-763
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• 2016

High temperature sodium/sulfur battery(Na/S battery) has good electrochemical properties, but, the battery has some problems such as explosion and corrosion at al. because of using the liquid electrodes at high temperature and production of high corrosion. Room temperature sodium/sulfur batteries (NAS batteries) is developed to resolve of the battery problem. To recently, room temperature sodium/sulfur batteries has higher discharge capacity than its of lithium ion battery, however, cycle life of the battery is shorter. Because, the sulfur electrode and electrolyte have some problem such as polysulfide resolution in electrolyte and reaction of anode material and polysulfide. Cycle life of the battery is improved by decrease of polysulfide resolution in electrolyte and block of reaction between anode material and polysulfide. If room temperature sodium/sulfur batteries (NAS batteries) with low cost and high capacity improves cycle life, the batteries will be commercialized batteries for electric storage, electric vehicle, and mobile electric items.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.156-158
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• 2018

The inconsistencies between paralleled battery cells are becoming more considerable issue in high capacity battery applications like electric vehicles. Due to differences in state-of-charge (SOC) and internal resistance within individual cells in parallel, charging or discharging current is not appropriately balanced to each cell in terms of SOC, which may shorten the lifetime or sometimes cause safety issues. In this paper, an intelligent cell-balancing algorithm is proposed to overcome the inconsistency issue especially for paralleled battery cells. In this scheme, SOC information collected in the sub-BMS module is sent to the main-BMS module, where the number of parallel cells to be connected to DC bus is continuously updated based on the suggested SOC comparison rule. To verify the method, operation of the algorithm on 4 paralleled battery cells are simulated on Matlab/Simulink. The simulation result shows that the SOCs of paralleled cells are evenly redistributed. It is expected that the proposed algorithm provides high reliable and prolong the life cycle and working capacity of the battery pack.