• 전기화학회지
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• 제4권3호
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• pp.132-137
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• 2001

최근 리튬이온전지를 채용한 노트북 PC의 수요는 계속 증가하고 있으며, 노트북 PC용 전지로는 잔존용량과 사용가능 시간을 정확하게 예측하며, 스스로 최적조건으로 충방전을 제어할 수 있는 SBP(smart battery pack)를 많이 채용하고 있다. SBP는 과충전, 과방전 및 과전류로부터 리튬이온전지의 안전성을 확보하기 위한 보호회로부 (protection IC)와 잔존용량 및 사용가능시간 등의 계산을 위한 지능회로부 (smart IC)로 구성되어있다. 보호회로는 충전 및 방전 FET를 이용하여 이상전류를 차단하며, SBS(smart battery system)는 system host, smart battery 및 smart battery charger로 구성되어 있다. 향후, SBP에 사용되는 IC는 저가이면서, 소비전류가 낮고, 소형화가 요구된다. 또한, microcomputer control type의 IC를 사용하고, 최적의 알고리즘을 개발하여 잔존용량 및 사용가능시간을 정확하게 예측할 필요가 있다. 이러한 SBS 기술은 노트북 PC 이외에도 전기자전거, 전기자동차, 전력저장용, 군사분야 등 광범위한 분야에서 사용될 것으로 예상된다.

• 전력전자학회논문지
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• 제17권6호
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• pp.553-561
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• 2012

Existing energy sources convert chemical energy into mechanical energy, while fuel cell directly generates electricity through an electrochemical reaction between hydrogen and oxygen. Therefore, it has a lot of strong points such as high efficiency, zero emission, and etc. In addition, with the development of hydrogen preservation technique, some companies have been researching and releasing portable fuel cell power packs for specific applications like military equipment, automobile, and so on. However, there are some drawbacks to the fuel cell, high cost and slow dynamic response. In order to compensate these weak points, auxiliary energy storages could be applied to the fuel cell system. In this paper, the optimum structure for a 150W portable fuel cell power pack with a battery pack is selected considering the specification of the system, and the design process of main parts is described in detail. Here, main objectives are compact size, simple control, high efficiency, and low cost. Then, an automatic mode change algorithm, which converts the operating mode depending on the states of fuel cell stack, battery pack, and load, is introduced. Finally, performance of the designed prototype using the automatic mode change control is verified through experiments.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.930-939
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• 2009

A bimodal tram is being developed to combine the flexibility of a bus with the punctuality of a train. The propulsion system is a series hybrid type using a set of CNG engine generator and Li-polymer battery. This paper presents the experimental results of the series hybrid propulsion power unit using an active loader which can simulate powering and regenerative braking conditions of the propulsion equipments continuously. The power sharing scheme between PWM converter and a battery pack has been observed. The measurement results of DC link voltage and SOC(State Of Charge) of battery pack are presented.

• 반도체디스플레이기술학회지
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• 제16권1호
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• pp.16-21
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• 2017

In this paper, the effect of battery-package shape of electric vehicle on the forced convection around a group of battery cells has been numerically investigated. Simulations for the two package shapes with straight/curved ducts have been conducted to examine the two design factors; the maximum temperature and the temperature deviation of a group of cells which influence the cell durability. The simulation of the conjugate heat transfer has been simplified by employing an equivalent thermal conductivity of cell that consists of various materials. It has been found that the maximum temperature and the temperature deviation of curved duct were lower than those of straight duct. Velocity fields have also been examined to describe the temperature distribution of a group of cells and the position of maximum temperature was found to be related to the dead zone of flow field.

• 전기화학회지
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• 제2권4호
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• pp.218-220
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• 1999

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.

• 대한기계학회논문집B
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• 제38권3호
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• pp.227-234
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• 2014

전기 자동차의 연료 소모량은 배터리 성능에 의존한다. 배터리의 성능은 작동온도에 민감하기 때문에, 배터리 온도 관리는 성능과 내구성을 보장한다. 특히, 배터리 팩에서의 모듈의 온도 분포는 냉각특성에 영향을 미친다. 이 연구는 모듈 사이의 온도 분포를 확인 할 수 있는 배터리 열적 모델링에 초점을 두었다. 본 연구의 배터리 모델은 NiMH 각형 모델이며, 10개의 모듈로 구성되어졌다. 배터리 열 모델은 열 발생, 채널을 통과하는 대류 열 전달 그리고 모듈 사이의 전도 열 전달로 구성되었다. 배터리 내에서 발생되는 열발생 모델은 충/방전 동안의 전기적인 저항열에 의해 계산되어 진다. 모델은 전 하이브리드 자동차의 운전 동안 적절한 열관리의 전략을 결정한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 추계학술대회 논문집
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• pp.200-201
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• 2013

This paper investigates a new approach for Li-Ion battery state-of-charge (SOC) estimation using sliding mode observer (SMO) technique including parameters aging compensation via recursive least squares (RLS). The main advantages of this approach would be low computational load, easiness of implementation along with the robustness of the method for internal battery model parameters estimation. The proposed algorithm was first tested on a set of acquired battery data using implementation in Simulink and later developed as C-code module for firmware application.

• 전기학회논문지
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• 제66권12호
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• pp.1889-1894
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• 2017

Global automobile manufacturers are developing electric vehicles (EVs) to eliminate the pollutant emissions from internal combustion vehicles and to minimize fossil fuel consumptions for the future generations. However, EVs have a disadvantage of shorter traveling distance than that of conventional vehicles. To answer this shortfall, more batteries are installed in the EV to satisfy the consumer expectation for the driving range. However, as the energy capacity of the battery mounted in the EV increases, the amount of heat generated by each cell also increases. Naturally, a better battery thermal management system (BTMS) is required to control the temperature of the cells efficiently because the appropriate thermal environment of the cells greatly affects the power output from the battery pack. Typically, the BTMS is divided into an active and a passive system depending on the energy usage of the thermal management system. Heat exchange materials usually include gas and liquid, semiconductor devices and phase change material (PCM). In this study, an application of PCM for a BTMS was investigated to maintain an optimal battery operating temperature range by utilizing characteristics of a PCM, which can accumulate large amounts of latent heat. The system was modeled using Dymola from Dassault Systems, a multi-physics simulation tool. In order to compare the relative performance, the BTMS with the PCM and without the PCM were modeled and the same battery charge/discharge scenarios were simulated. Number of analysis were conducted to compare the battery cooling performance between the model with the aluminum case and PCM and the model with the aluminum case only.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.1467-1468
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• 2013

• 전력전자학회논문지
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• 제26권6호
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• pp.381-389
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• 2021

Most diagnosis approaches rely on historical failure data that might not be feasible in real operating conditions because the battery voltage and internal parameters are nonlinear according to various operating conditions, such as cell-to-cell configuration and initial condition. To overcome this issue, the estimator and the predictor require integrated approaches that consider comprehensive data, with the degradation process and measured data taken into account. In this paper, vector autoregressive models (VAR) with various parameters that affect overdischarge to the cell in the battery pack were constructed, and the cell-to-cell parameters were identified using an adaptive model to analyze the influence of failure prognosis. The theoretical analysis is validated using experimental results in terms of the feasibility and advantages of fault prognosis.