배터리 열관리를 위한 개선된 발열 모사체 연구

함세현(Se Hyeon Ham),권준호(Junho Kwon),김용찬(Yongchan Kim) 대한설비공학회 2021 대한설비공학회 학술발표대회논문집 Vol.2021 No.6

하이브리드 자동차 열관리를 위한 리튬 이온 배터리 열관리 2차원 모델링

한재영(Jaeyoung Han),김성수(SungSoo Kim),유상석(Sangseok Yu) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11

EVs and Hybrid electric vehicles depends strongly on their battery affects. The performance of the battery is sensitive to battery temperature and the temperature of the battery will affect the reliability of the battery and improve performance and extend the life. In particular, the temperature distribution of cell to cell in battery pack differ for cooling characterisrics and cooling methode. It is desirable to have a temperature distribution of <5°C from cell to cell. Appropriate modeling for Automotive application battery thermal management shortens the battery design and development process. This study presents temperature distribution between cell for cooling characterisrics and cooling methode through a two-dimensional using the Matlab/Simulinkⓡ. The battery assumes prismatic and consists of 10 cell. Battery thermal management model consists heat generation, heat transfer and pressure drop. Especially The heat generation model considers charge/discharge state. Therefore, this study confirms temperature distribution of between cell for appropriate battery thermal management, and By applying the integrated model of a lithium-ion battery, while driving the battery to ensure proper thermal management.

원통형 18650 LiFePO4 배터리의 충⋅방전 주기 동안의 열 거동

정인아,강창우,안성필 대한기계학회 2024 大韓機械學會論文集B Vol.48 No.5

본 연구에서는 2차원 전기-열적 모델을 이용하여 충·방전 주기 동안 원통형 18650 LiFePO4 배터리의 열적 거동을 예측을 수행한다. 강제대류 조건에서 충전율(C-rate)과 배터리 표면에서의 대류 열전달계수를 변화시키며 배터리 내부의 온도 분포를 분석한다. 특정 충 · 방전 횟수 이후 배터리는 일정한 온도 범위를 갖는 정상상태에 도달한다. 충전율(C-rate)이 커지면 배터리 내부 발생열은 증가하며 이는 곧 배터리의 온도 상승으로 이어진다. 반면, 대류 열전달 계수가 커지면 배터리 내부 발생열을 주위로 더욱 효과적으로 소산하여 배터리 온도가 감소한다. 본 연구 결과로 LiFePO4 배터리의 안전한 운용을 위해서 대류 열전달 계수가 최소 10 W/m2K 이상인 강제 대류 조건에서 배터리가 작동되어야 함을 확인할 수 있다. A two-dimensional electro-thermal model is used to predict the thermal behavior of a cylindrical 18650 LiFePO4 battery during charge and discharge cycles. Under a forced convection, current rate and convective heat transfer rate on the surface of the lithium-ion battery are varied to analyze the temperature distributions in the battery. After several charge and discharge cycles, the battery achieves a steady-state with a constant temperature range. The maximum temperature in the battery increases with the increase in the current rate that enhances the heat generation, whereas the increasing convective heat transfer rate reduces the temperature of the battery by dissipating the heat to the surroundings. The thermal behavior shows that the LiFePO4 battery should be operated under forced convection conditions with a convective heat transfer rate of at least 10 W/m2K for safe battery driving.

모델링에 기반한 전기자동차 배터리 열관리 시스템의 영향

최종우(Jongwoo Choi),조구영(Gooyoung Cho),박준호(Joonho Park),임재환(Jaehwan Lim),정하철(Hachul Jeong),차석원(Suk-Won Cha) 한국자동차공학회 2011 한국자동차공학회 학술대회 및 전시회 Vol.2011 No.11

In this paper, effects of battery thermal management system was simulated. As increasing needs of HEV and EV, keeping battery temperature to their optimum condition is now one of the most important topics in battery research area. Battery thermal management system helps to keep optimum temperature condition by controlling cooling and heating system. However, it needs electrical power to work, which directly decreases SOC of the battery. Thus, battery thermal management system has both positive and negative effect to the HEV and the EV. To show these effects, battery thermal management system model was made and simulated. Modeling and simulation were done by using Autonomie<SUP>®</SUP> and MATLAB<SUP>®</SUP>.

리튬이온 배터리의 열관리가 전기자동차 주행거리에 미치는 영향

박철은(Chul-Eun Park),유세웅(Se-Woong Yoo),정영환(Young-Hwan Jeong),김기범(Kibum Kim) 한국산학기술학회 2017 한국산학기술학회논문지 Vol.18 No.5

전기자동차에 사용되는 리튬이온 배터리의 성능은 배터리 온도에 따라 큰 차이를 보인다. 본 논문에서는 유한차분법을 이용하여 배터리의 발열량에 따른 배터리의 온도변화를 평가하고, 배터리의 충전량, 내부저항 및 전압변화를 조사하였다.이 배터리 모델을 1차원 해석 프로그램인 AMESim과 연동하여 전기자동차가 NEDC 모드로 주행 시, 배터리의 온도 변화에 따른 전기자동차의 주행거리를 산출하였다. 배터리는 온도가 25℃ 이하로 감소하면 내부저항이 증가하기 때문에 발열량이 증가하여 주행거리는 줄었다. 또한, 배터리의 온도가 25℃ 이상이 되면, 배터리의 충전량이 감소하여 배터리의 성능이 떨어지고 그 결과로 주행거리가 줄었다. 배터리의 성능을 최적으로 유지할 수 있는 온도인 25℃를 기준으로 배터리의 온도가 -20℃와 45℃일 때, 전기자동차의 주행거리는 각각 33%와 1.8% 감소하였다. 배터리의 최적 온도를 유지하기 위해 효율적인 배터리 열관리를 통하여 저온에서는 가열, 고온에서는 냉각이 이루어져야 한다. 해석 결과 외기온이 -20℃인 경우 500 W의 열을 공급해주어야 하며, 외기온이 45℃ 경우에는 냉방을 통해 250 W의 열을 방출해줌으로써 배터리 구동의 최적 온도인 25℃를 유지할 수 있다. The performance of lithium ion batteries used in electric vehicles (EV) varies greatly depending on the battery temperature. In this paper, the finite difference method was used to evaluate the temperature change, state of charge (SOC), internal resistance, and voltage change of the battery due to heat generation in the battery. The simulation model was linked with AMESim to calculate the driving range of an EV traveling in New European Driving Cycle (NEDC) mode. As the temperature dropped below 25℃, the internal resistance of the battery increased, which increased the amount of heat generated and decreased the driving range of EV. At battery temperatures above 25℃, the driving range was also decreased due to reduced SOC that deteriorated the battery performance. The battery showed optimal performance and the driving range was maximized at 25℃. When battery temperatures of -20℃ and 45℃, the driving range of EV decreased by 33% and 1.8%, respectively. Maintaining the optimum battery temperature requires heating the battery at low temperature and cooling it down at high temperature through efficient battery thermal management. Approximately 500 W of heat should be supplied to the battery when the ambient temperature is -20℃, while 250 W of heat should be removed for the battery to be maintained at 25℃.

신소재를 활용한 열관리 시스템 해석과 시스템 레벨에서의 효과 분석

강민우(Minwoo Kang),한상현(Sanghyeon Han),최웅철(Woongchul Choi) 한국자동차공학회 2018 한국자동차공학회 학술대회 및 전시회 Vol.2018 No.11

The effective operating temperature of a lithium-ion battery is usually around 30 to 40 °C. If the temperature of the battery inside the electric vehicle is higher than the specified operating range, the life and efficiency of the battery may deteriorate. Also, in worst case, excessive battery heat may cause fire or explosion of the system. Therefore, Battery Thermal Management System (BTMS) is essential to keep battery temperature within the appropriate operating temperature range. In this study, the goal is to assess the applicability of newly developed material, mainly a carbon based graphite with enhanced thermal conductivity, as a medium to move the heat away from the cell in the BTMS. To verify applicability of the new material, ANSYS Fluent was used to perform thermal transfer analysis computationally and physical experiments using a heating element were carried out to strengthen results from the numerical analysis. Based on simulation results and supporting experimental results, current research provides the basis for the possible application of the new material as a part of advanced battery pack for successful EV thermal management. As mentioned in the conclusion section, it shows a clear advantage in the weight reduction area while keeping the thermal characteristics of battery pack as stable as required for the safe operation.

PCM 종류에 따른 18650 리튬-이온 셀 모듈의 냉각 특성 연구

유시원,김한상 한국수소및신에너지학회 2020 한국수소 및 신에너지학회논문집 Vol.31 No.6

The performance and cost of electric vehicles (EVs) are much influenced by the performance and service life of the Li-ion battery system. In particular, the cell performance and reliability of Li-ion battery packs are highly dependent on their operating temperature. Therefore, a novel battery thermal management is crucial for Li-ion batteries owing to heat dissipation effects on their performance. Among various types of battery thermal management systems (BTMS'), the phase change material (PCM) based BTMS is considered to be a promising cooling system in terms of guaranteeing the performance and reliability of Li-ion batteries. This work is mainly concerned with the basic research on PCM based BTMS. In this paper, a basic experimental study on PCM based battery cooling system was performed. The main purpose of the present study is to present a comparison of two PCM-based cooling systems (n-Eicosane and n-Docosane) of the unit 18650 battery module. To this end, the simplified PCM-based Li-ion battery module with two 18650 batteries was designed and fabricated. The thermal behavior (such as temperature rise of the battery pack) with various discharge rates (c-rate) was mainly investigated and compared for two types of battery systems employing PCM-based cooling. It is considered that the results obtained from this study provide good fundamental data on screening the appropriate PCMs for future research on PCM based BTMS for EV applications.

전기자동차용 축전지의 발열량 측정을 위한 열용량계 개발

양철남,박성용,Yang Cheol-Nam,Park Seong-Yong 한국전기화학회 1999 한국전기화학회지 Vol.2 No.4

EV & HEV의 성능은 다수의 축전지로 구성된 축전지팩의 성능에 좌우된다. 축전지의 열적 특성도 이러한 축전지팩의 성능을 좌우하는 많은 인자중의 하나이다. 특히 축전지의 열적 특성은 차량의 주행성능 및 축전지의 수명주기에 큰 영향을 주기 때문에, 축전지에서 발생되어 나오는 열량은 차량의 주행 모드를 모사한 다양한 조건하에서 가능한 정확히 측정되어야 한다. 또한 EV & HEV용 축전지팩의 열관리 시스템을 설계하기 위해서는 축전지팩내의 축전지에 대한 정확한 열특성 데이터를 필요로 하고 있다. 그러나 기존의 열량계로서는 EV용 축전지를 수용하여 열측정 시험을 하기엔 공동(Cavity)크기가 너무 작다. 이에 EV용 축전지의 열적 특성을 시험하기 위한 열량계를 공동(Cavity)의 크기 $120mm\times75mm\times200mm$로 개발하였다. 열량계의 보정은 0-200 W의 Heat Rate를 발생시킬 수 있는 가상셀(Dummy Cell)을 주문 제작하여 행하였다. 실제 입력 열량에 대한 측정열량의 오차범위는 $2\%$ 이내였고, 측정에 따른 전위 안정성도 2.5 mV 이내였다. The performance of the Electric Vehicle and Hybrid Electric Vehicle depends on that of the battery pack composed of series connected batteries. And thermal property is one of the main factors which decide the performance of the battery pack. So heat generation rate from the battery under the various driving mode must be measured as precise as possible because thermal characteristics of the battery affect the driving performance and battery pack's life cycle. Besides, to design and develop the battery thermal management system for the EV and HEV, the measurements of the thermal properties of the batteries are needed. However, the established calorimeter is not adequate to test an EV's battery because its cavity is too small to accommodate the EV's battery. Therefore we developed the calorimeter to test the thermal property of the EV's battery. Its cavity size is 120mm long, 75mm wide and 200mm high. The calorimeter is calibrated by the dummy cell which generates the heat rate from zero to 200W. The measuring accuracy of the calorimeter is within $2\%$ and its voltage stability is 2.5mV in the constant temperature bath.

Development of Battery Management System for Electric Vehicle Applications of Ni/MH Battery

Jung Do Yang,Lee Baek Haeng,Kim Sun Wook The Korean Electrochemical Society 2001 한국전기화학회지 Vol.4 No.4

전기자동차의 성능은 축전지의 성능에 의해 크게 좌우된다. 그러므로 우수한 성능과 높은 신뢰성을 가진 전기자동차를 개발하기 위해서는 다양한 운영조건에서 축전지가 최대의 성능을 가질 수 있게 잘 관리되어야 한다. 축전지의 성능 향상은 축전지 관리 시스템(BMS)의 적용에 의해 달성될 수 있으며 BMS는 축전지의 상태 감시뿐만 아니라 축전지의 충전 및 방전을 최적화하는 중요한 역할을 수행한다. 이 연구에서는 전기자동차에 적용된 니켈 메탈하이드라이드 전지(Ni/MH battery) 이용을 최대화하기 위한 역할을 수행하는 BMS를 개발하였다 이 시스템은 축전지의 충전 및 방전 제어, 과충전 및 과방전 방지, 잔존용량 계산 및 표시, 안전관리 및 열관리 등의 기능을 가진다. 금번 개발된 BMS를 대우자동차와 고등기술원이 공동 개발한 DEV5-5전기자동차에 장착하여 시험을 수행하였다. 이 차량에는 파나소닉사의 12V-95Ah사양의 Ni/MH battery 18모듈이 적용되었다 시험결과 이 시스템은 $3\%$ 이내의 높은 정확성을 가지고 있으며 우수한 신뢰성을 나타내었다. 이 BMS는 전기자동차의 신뢰성과 안전도뿐만 아니라 Ni/MH battery pack의 성능과 수명을 향상시킬 것이다. Electric vehicle performance is very dependent on traction batteries. For developing the electric vehicles with high performance and good reliability, the traction batteries have to be managed to get maximum performance under various operating conditions. The enhancement of the battery performance can be accomplished by implementing battery management system (BMS) that plays important roles of optimizing the control mechanism of charge and discharge of the batteries as well as monitoring battery status. In this study the battery management system has been developed for maximizing the use of Ni/MH batteries in electric vehicle. This system provides several tasks: the control of charging and discharging, overcharge and over-discharge protection, the calculation and display of state of charge, safety and thermal management. The BMS was installed in and tested using the DEV5-5 electric vehicle developed by Daewoo Motor Co. and Institute for Advanced Engineering in Korea. The 18 modules of Panasonic Ni/MH battery, 12 V-95 Ah, were used in the DEV5-5. The high accuracy within the range of $3\%$ and the good reliability were shown in the test results. The BMS can also improve the performance and cycle life of Ni/MH battery pack as well as the reliability and safety of the electric vehicles (EV).

Heat transfer characteristics of the integrated heating system for cabin and battery of an electric vehicle under cold weather conditions

Seo, Jae-Hyeong,Patil, Mahesh Suresh,Cho, Chong-Pyo,Lee, Moo-Yeon Elsevier 2018 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.117 No.-

<P><B>Abstract</B></P> <P>The objective of this study is numerically to investigate the heat transfer characteristics of the integrated heating system considering the temperature of cabin and battery of an electric vehicle under the cold weather conditions. The integrated heating system consists of a burner to combust fuel, an integrated heat exchanger for CHE (coolant heat exchanger) and AHE (air heat exchanger). The heat transfer characteristics like the overall heat exchanger effectiveness, the heat transfer rate, the temperature distribution and the fluid flow characteristics like the pressure drop, velocity distribution of the investigated integrated heating system were considered and analyzed by varying the inlet mass flow rates and the inlet temperatures of the cold air and water, respectively. The average Nusselt numbers for the cold air side and the water side were increased 28.4% and 9.5%, respectively, with the increase of the cold air side Reynolds numbers from 15,677 to 72,664 and the water side Reynolds numbers from 4330 to 11,912. The numerical results showed good agreement within ±9.0% of the existed data and thus confirmed that the present model was valid. In addition, the proposed integrated heating system could be used as the thermal management of the cabin and the battery system of the electric vehicle under the cold weather conditions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> EVs have issues on cabin heating source and battery heating under cold weather. </LI> <LI> EVs suffer from a short driving range and shortage of cabin heating. </LI> <LI> Cabin air heating and battery thermal management for electric vehicle investigated. </LI> <LI> The considered system was investigated under various operating conditions. </LI> <LI> Integrated heating system suggested for cabin heating and battery thermal management. </LI> </UL> </P>