• Proceedings of the KIPE Conference
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• 2010.11a
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• pp.351-353
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• 2010

본 논문에서는 쉽고 빠르게 정확한 리튬 이온 배터리 모델을 구현할 수 있는 방법을 제시하고 있으며, 구현된 모델을 MATLAB(R)/Simulink(R)환경에서 검증한다. 모델을 구현함에 있어서 절차를 간소화하기 위해 비선형 개방 전압은 배터리 충전 및 방전 전압의 평균으로 근사하고, 배터리 내부 비선형 파라미터는 방전 초기에 발생하는 과도응답을 측정한 이산 데이터를 곡선 접합하여 구한다. 구현된 모델을 이용하여 시뮬레이션을 하고 이를 실험 데이터와 비교해본 결과, 평균 절대오차는 기존 연구보다 0.1% 낮은 0.091%로 측정되었다. 측정된 오차의 수준은 본 논문에서 제안한 방법이 파라미터 추출에 필요한 시간을 단축하고 시뮬레이션 모델을 쉽게 구현 가능하게 함에도 불구하고 여전히 리튬 이온 배터리의 출력 특성을 정확하게 예측함을 보여준다.

• Smart Media Journal
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• v.12 no.11
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• pp.103-112
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• 2023

Recently, the need to prevent battery fires and accidents has emerged, as the use of lithium-ion batteries has increased. In order to prevent accidents, it is necessary to predict the state of health (SOH) and check the replacement timing of the battery with a lot of degradation. This paper proposes a model for predicting the degradation state of a battery by using four battery degradation indicators: maximum voltage arrival time, current change time, maximum temperature arrival time, and incremental capacity (IC) that can be obtained in the battery charging process, and LSTM using an attention mechanism. The performance of the proposed model was measured using the NASA battery data set, and the predictive performance was improved compared to that of the general LSTM model, especially in the SOH 90-70% section, which is close to the battery replacement cycle.

• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.169-170
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• 2017

본 논문에서는 Matlab을 이용하여 배터리의 전기적 모델과 내부 파라미터 추출 통해 시뮬레이션을 하였다. IR-drop에 의해 변화한 전압 데이터를 이용하여 부하 전류 변화로 인한 시뮬레이션과 실험 데이터 간의 오차 개선함으로써 배터리 전기적 모델과 실험 전압 데이터를 이용함으로써 확장 칼만 필터(extended kalman filter; EKF) 같은 적응 알고리즘을 사용하지 않고도 오차가 감소된 시뮬레이션이 가능함을 확인하였다.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.439-440
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• 2019

리튬 이온 배터리가 전기 자동차 및 다양한 어플리케이션에 적용됨에 따라 폐배터리의 수요 또한 증가하고 있다. 내부 화학적 상태가 상이한 배터리의 전기적 특성실험을 통해 파라미터를 선정하였으며, 데이터의 분포에 적합한 Fuzzy Logic을 설계하였다. 설계된 Fuzzy Logic을 통한 Cell Grading으로 내부 화학적 특성이 유사한 셀을 선별하였다.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.727-730
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• 2023

The operation of electric automatic windows is used in harsh environments, and the energy density decreases as charging and discharging are repeated, and as soundness deteriorates due to damage to the internal separator, the vehicle's mileage decreases and the charging speed slows down, so about 5 to 10 Batteries that have been used for about a year are classified as waste batteries, and for this reason, as the risk of battery fire and explosion increases, it is essential to diagnose batteries and estimate SOH. Estimation of current battery SOH is a very important content, and it evaluates the state of the battery by measuring the time, temperature, and voltage required while repeatedly charging and discharging the battery. There are disadvantages. In this paper, measurement of discharge capacity (C-rate) using a waste battery of a Tesla car in order to predict SOH estimation of a lithium-ion battery. A Support Vector Machine (SVM), one of the machine models, was applied using the data measured from the waste battery.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.130-132
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• 2020

배터리 시스템은 어플리케이션의 대영화에 따른 데이터 저장공간 문제 및 연속적인 배터리 신뢰성 문제 해결을 위한 건전성 예측 및 관리기술 접목에 관한 문제에 직면해 있으며, 이러한 문제 해결을 위해서는 배터리 시스템 신호를 통해 추출 가능한 건전성 지표 수립이 중요하다. 본 논문은 건전성 지표를 물리적, 간접적 지표로써 정의하고, 사이클 노화 데이터를 통해 건전성 지표로써의 성능을 검증하였다.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.212-214
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• 2020

리튬이온 배터리를 고온의 환경에서 장시간 운용함에 따라 배터리 내부 물질의 변형 및 특성 변화가 발생하여 안전성의 문제가 발생하게 된다. 배터리의 안전성을 향상하기 위해 배터리의 고장 및 이상 상태를 진단 및 탐지하는 기법들의 연구가 진행되고 있다. 본 논문에서는 배터리의 이상 상황을 모사하기 위해 열폭주의 한 가지 방법인 고온의 환경에서 배터리의 특성 변화를 전기화학적 임피던스 분광법을 통해 분석하였으며, 등가회로 모델의 특성 인자를 활용하여 이상 상황을 탐지할 수 있는 이동 평균 추세선 기반의 이상 탐지 기법을 제안하며, 열폭주가 발생한 데이터를 통해 이상 탐지 기법을 검증한다.

• Journal of Hydrogen and New Energy
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• v.32 no.6
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• pp.592-611
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• 2021

In this study a rarely available high-throughput cycling data set of 124 commercial lithium iron phosphate/graphite cells cycled under fast-charging conditions, with widely varying cycle lives ranging from 150 to 2,300 cycles including in-cycle temperature and per-cycle IR measurements. We worked out own Python codes which reproduced the various data plots and machine learning approaches for cycle life prediction using early cycles and more details not presented in the article and the supplementary information. Particularly, we applied regularized ridge, lasso and elastic net linear regression models using features extracted from capacity fade curves, discharge voltage curves, and other data such as internal resistance and cell can temperature. We found that due to the limitation in the quantity and quality of the data from costly and lengthy battery testing a careful hyperparameter tuning may be required and that model features need to be extracted based on the domain knowledge.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.1
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• pp.28-33
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• 2016

Batteries are used for main power engine in the fields such as mobiles, electric vehicles and unmanned submarines, for starter and lamp driver in general automotive, for emergency electric source in ship. These days, lead-acid and the lithium ion batteries are increasingly used in the fields of the secondary battery, and the lead-acid battery has a low price and safety comparatively, The lithium ion battery has a high energy density, excellent output characteristics and long life, whereas it has the risk of explosion by reacting with moisture in the air. But Recently, due to the development of waterproof, fireproof, dustproof technology, lithium batteries are widely used, particularly, because their usages are getting wider enough to be used as a power source for hybrid ship and electric propulsion ship, it is necessary to manage more strictly. Hybrid ship has power supply units connected to the packets to produce more than 500kWh large power source, and therefore, A number of the communication modules and wires need to implement the wire inspection and monitor system(WIIMS) that allows monitoring server to transmit detecting voltage, current and temperature data, which is required for the management of the batteries. This paper implements a low price type wireless inspection and monitoring system(WILIMS) of the lithium ion battery for hybrid vessels using BLE wireless communication modules and power line modem( PLM), which have the advantages of low price, no electric lines compared to serial communication inspection systems(SCIS). There are state of charge(SOC), state of health(SOH) in inspection parts of batteries, and proposed system will be able to prevent safety accidents because it allows us to predict life time and make a preventive maintenance by checking them at regular intervals.

• Journal of IKEEE
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• v.23 no.1
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• pp.1-8
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• 2019

In this paper, the electrical characteristics with various C-rates are tested with a high power series battery pack comprised of 18650 cylindrical nickel cobalt aluminum(NCA) lithium-ion battery. The electrical characteristics of discharge capacity test with 14S1P battery pack and electric vehicle (EV) cycle test with 4S1P battery pack are compared and analyzed by the various of C-rates. Multiple linear regression is used to estimate voltage imbalance of 14S1P and 4S1P battery packs with various C-rates based on experimental data. The estimation accuracy is evaluated by root mean square error(RMSE) to validate multiple linear regression. The result of this paper is contributed that to use for estimating the voltage imbalance of discharge capacity test with 14S1P battery pack using multiple linear regression better than to use the voltage imbalance of EV cycle with 4S1P battery pack.