• 전기학회논문지
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• 제60권10호
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• pp.1875-1880
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• 2011

This paper proposes a battery model applicable to Autonomie environment. Also, a various of experiment is implemented for validation. The proposed battery model modifies Randles equivalent circuit and battery parameters are extracted from pulsed current tests. The parameters are two-dimensional function of current and SOC(State of Charge). The battery model is developed in the Matlab/Simulink and is implemented for NiMH Panasonic HHR650D and compared with pulsed current discharge curves. The simulation results validate the accuracy of the proposed model and the model is also tested by adding it on Autonomie for HEV application. Constant current charge/discharge, pulsed current test that can be used to extract battery parameter are performed and test results are used to build up the proposed battery model for Autonomie.

• 대한임베디드공학회논문지
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• 제8권4호
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• pp.213-218
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• 2013

In this research, we report on the development of simulation system for performance verification of BMS(Battery Management System) which is utilized in electric vehicles. In the industrial circles, a manufacturer of BMS typically tests their system with real battery packs. However, it takes a long time to test all functions of BMS. Here, we develop BMU(Battery Managament Unit) as an embedded board, which will be installed in electric vehicle for controlling battery packs. All other environment factors for testing BMU are developed in softwares in order to reduce the term of test. Especially, the proposed system consists of cell simulator and CMU(Cell Management Unit) simulator which simulate real battery cells and control battery cells. These simulators enable the BMU to test more battery cells. In addition, proposed system provides diagnosis program in order to diagnose and monitor the condition of BMS which makes the test of BMS more easily. In order to verify the performance of the developed simulator, we have performed the experiment with real battery packs and our simulator. Through comparing two results of experiments, we verify that developed simulator shows better performance in terms of less amount of testing duration though having high reliability.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.600-605
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• 2003

Battery of rolling stock is a very important device as power supply at starting and emergency control. This paper analyzes the quality of Ni-Cd battery by means of performance test. Ni-Cd battery have suitable and stable properties. That is very stable to discharge on low temperature state and very easy to manage and repair. This paper confirm the performance and property of Ni-Cd battery on low temperature environment by the performance test and estimate the life-cycle of Ni-Cd battery on board at rolling-stock by the life-test and the using-test.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.339-340
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• 2012

• Journal of Electrochemical Science and Technology
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• 제15권3호
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• pp.414-420
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• 2024

Lithium-ion batteries are widely used in many applications due to their high energy density, high efficiency, and excellent cycle ability. Once an unknown Li-ion battery is reusable, it is important to measure its lifetime and state of health. The most favorable measurement method is the cycle test, which is accurate but time- and capacity-consuming. In this study, instead of a cycle test, we present an empirical model based on the C-rate test to understand the state of health of the battery in a short time. As a result, we show that the partially accelerated charge/discharge condition of the Li-ion battery is highly effective for the degradation of battery capacity, even when half of the charge/discharge conditions are the same. This observation provides a measurable method for predicting battery reuse and future capacity degradation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 춘계학술대회 논문집 전기설비전문위원
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• pp.123-124
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• 2008

Battery is one of the emergency power. Battery reliability is a very important to keep up the minimum of building capabilities in case of interruption of electric power. Instantaneous discharge test is carried out for measuring transient voltage change(${\Delta}V$) and internal instantaneous impedance(Z), and then it is compared with discharge test results for the estimating the battery capacity. As a result, it was confirmed that the voltage change(${\Delta}V$) and the instantaneous impedance of the batteries failed in actual discharge test were higher that those of the sound batteries. Such an instantaneous discharge test can be a diagnosis of battery sound.

• 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.

• 융복합기술연구소 논문집
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• 제11권1호
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• pp.19-23
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• 2021

These days, sales of battery electric vehicles have been rapidly increasing due to the strict CO₂ regulations. However, since it take too long to measure the energy economy of electric vehicles, it has been required to improve the procedure of energy economy measurement. In order to improve this problem, the present study analyzed the battery charge/discharge pattern according to the changes in battery SOC (state of charge). In general, the energy economy test is started with a battery SOC charged to 100 %. However, it was identified that when the battery is fully charged, it can actually be charged over the 100 % (e.g., 100.5 %). This can induce errors in the energy economy measurement. Therefore, the present study recommend to start the test at SOC 99.9 %. The regenerative braking was partly restricted for the SOC over 90 %. This made it difficult to estimate the overall energy economy of the electric vehicle. However, it was identified that there was no change in the battery charge/discharge characteristics under the SOC 90 %. Therefore, the energy economy test can be shortened by predicting the overall energy economy through a short mileage test.

• 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.

• 한국지열·수열에너지학회논문집
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• 제18권3호
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• pp.7-18
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• 2022

Secondary batteries used in electric vehicles have a potential risk of ignition and explosion. Various safety measures are being taken to prevent these risks. A numerical study was performed using a computational fluid dynamics code on the cases where pressure relief vents that can reduce the blast overpressures of batteries were installed in the through-compression test room, short-circuit drop test room, combustion test room, and immersion test room in facilities rleated to battery used in electric vehicles. This study was conducted using the weight of TNT equivalent to the energy release from the battery, where the the thermal runaway energy was set to 324,000 kJ for the capacity of the lithium-ion battery was 90 kWh and the state of charge (SOC) of the battery of 100%. The explosion energy of TNT (△H_TNT) generally has a range of 4,437 to 4,765 kJ/kg, and a value of 4,500 kJ/kg was thus used in this study. The dimensionless explosion efficiency coefficient was defined as 15% assuming the most unfavorable condition, and the TNT equivalent mass was calculated to be 11 kg. The internal explosion generated in a test room shows the very complex propagation behavior of blast waves. The shock wave generated after the explosion creates reflected shock waves on all inner surfaces. If the internally reflected shock waves are not effectively released to the outside, the overpressures inside are increased or maintained due to the continuous reflection and superposition from the inside for a long time. Blast simulations for internal explosion targeting four test rooms with pressure relief vents installed were herein conducted. It was found that that the maximum blast overpressure of 34.69 bar occurred on the rear wall of the immersion test room, and the smallest blast overpressure was calculated to be 3.58 bar on the side wall of the short-circuit drop test room.