• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.436-437
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• 2018

This paper describes the structure and design of a modular DC/DC converter for connecting DC sources such as battery, solar cell, etc. to DC distribution network. The modular converter structure of IPOS type and the optimal design and implementation of the unit converter cell are discussed.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 춘계학술대회
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• pp.735-737
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• 2017

An Off grid or remote solar electric systems are an energy supply to our home or to our companies without the utility of Grid at all. Off grid solar systems are very important for those who live in remote locations especially for developing countries where getting the electric grid is extremely expensive, inconvenient or for those who doesn't need to pay a monthly bill with the electric bill in general. The main critical components of any solar power system or renewable energy harvesting systems are the energy storage systems and its charge controller system. Energy storage systems are the essential integral part of a solar energy harvesting system and in general for all renewable energy harvesting systems. To provide an optimal solution of both high power density and high energy density at the same time we have to use hybrid energy storage systems (HESS), that combine two or more energy storage technologies with complementary characteristics. In this present work, design and simulation we use two storage systems supercapacitor for high power density and lithium based battery for high energy density. Here the system incorporates fast-response supercapacitors to provide power to manage solar smoothing and uses a battery for load shifting. On this paper discuss that the total energy throughout of the battery is much reduced and the typical thermal stresses caused by high discharge rate responses are mitigated by integrating supercapacitors with the battery storage system. In addition of the above discussion the off grid solar electric energy harvesting presented in this research paper includes battery and supercapacitor management system, MPPT (maximum power point tracking) system and back/boost convertors. On this present work the entire model of off grid electric energy harvesting system and all other functional blocks of that system is implemented in MATLAB Simulink.

• 품질경영학회지
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• 제38권4호
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• pp.580-586
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• 2010

Performance variations in mixture products such as medicine, food, and chemicals can be caused by their own subcomponents. For instance, a discharge capacity of a lithium-ion battery depends upon the mixture ratio of ethylene, dimethyle, and ethyle-methyle, all of which are subcomponents of an electrolyte solution in the battery. Thus it is crucial to determine tolerances of the mixture ratio in order to maintain the product quality at a desired level. This paper is concerned with the tolerance design of the mixture ratio. In particular, minimizing variance around the mixture ratio is adopted as a decision criterion in this paper. An illustrative example with multiple quality characteristics is given as well.

• 전력전자학회논문지
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• 제24권3호
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• pp.181-190
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• 2019

Active power decoupling circuits have emerged to eliminate the inherent second-order ripple power in a single-phase power conversion system. This study proposes a design method to determine the optimal capacitance for active power decoupling circuits to achieve high power density. Minimum capacitance is derived by analyzing ripple power in a passive power decoupling circuit, a buck-type circuit, and a capacitor-split-type circuit. Double-frequency ripple power decoupling capabilities are also analyzed in three decoupling circuits under a 3.3 kW load condition for a battery charger application. To verify the proposed design method, the performance of the three decoupling circuits with the derived minimum capacitance is compared and analyzed through the results of MATLAB -Simulink and hardware-in-the-loop simulations.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.727-730
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• 2002

Most of battery industries are growing explosively as a core strategy industry for the development of the semi-conductor, the LCD, and the mobile communication device. Dynamic characteristic analysis consists of dynamic behavior analysis and finite element analysis and is necessary for effective design of machines. In the dynamic behavior analysis, the displacement, velocity, applied force and angular velocity of each components are simulated according to each part. In the FEA, stress analysis, mode analysis, and frequency analysis are performed far each part. The results of these simulations are used for the design specification investigation and compensation for optimal design of cell manufacturing line. Virtual Engineering of the separator inserting machine on the automatic cell assembly line systems are modeled and simulated. 3D motion behavior is visualized under real-operating condition on the computer window. Virtual Prototype make it possible to save time by identifying design problems early in development, cut cost by reducing making hardware prototype, and improve quality by quickly optimizing full-system performance. As the first step of CAE which integrates design, dynamic modeling using ADAMS and FEM analysis using NASTRAN are developed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.274-276
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• 2008

This paper proposes an individual charge equalization converter using selective two current paths for series connected lithium-ion battery strings. In the proposed equalizer, a central equalization converter acting as a controllable current source is sequentially connected in parallel with individual batteries through an array of cell selection switches. A flyback converter with a modified rectifier realizes a controllable current source. A central equalization converter is shared by every battery cells through the cell selection switch, instead of a dedicated charge equalizer for each cell. With this configuration, although the proposed equalizer has one dc-dc converter, individual charge equalization can be effectively achieved for the each cell in the strings. Furthermore, since the proposed equalizer would not allocate the separated dc-dc converter to each cell, such that the implementation of great size reduction and low cost can be allowed. In this paper, an optimal power rating design guide is also employed to obtain a minimal balancing size while satisfying equalization requirements. A prototype for eight lithium-ion battery cells is optimally designed and implemented. Experimental results verify that the proposed equalization method has good cell balancing performance showing small size, and low cost.

• 예술인문사회 융합 멀티미디어 논문지
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• 제9권5호
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• pp.865-872
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• 2019

본 논문은 한국교통대학교 태양광 자작 자동차 동아리 늘해랑에서 WSC(World Solar Challenge)에 참가하기 위해 제작한 Solar Car 구동시스템에 대하여 서술한다. WSC는 세계 최대의 태양광 자동차 경주 대회로 별도의 자동차 규정을 가지고 있어 태양전지 면적이나 배터리 용량등에 제약을 두기 때문에, 제한된 규정내에서 최대 에너지 효율을 가지도록 구동시스템을 설계하는 것이 가장 중요한 기술적인 팩터이다. Solar car의 구동시스템은 태양광 에너지를 전기 에너지로 변환해주기 위한 solar array, 변환된 전기에너지를 최대 출력으로 추적하기 위한 MPPT(Maximum Power Point Tracker) controller, 생산된 전기에너지를 저장하기 위한 battery, 전기에너지를 역학에너지로 변환하여 차량 구동을 위한 BLDC(Brushless DC) motor, BLDC motor를 제어하기 위한 motor controller 등으로 구성되어 있다. 본 연구에서는 최적 구동 시스템을 위해 태양전지 에너지 변환 시스템과 배터리, 모터로 구성된 전기 구동시스템 설계에 대한 내용을 포함하고 있다.

• 소성∙가공
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• 제29권5호
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• pp.272-281
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• 2020

As the thickness of mobile communication devices is getting thinner, the size of the internal parts is also getting smaller. Among them, the battery case requires a high-level deep drawing technique because it has a rectangular shape with a large aspect ratio. In this study, the initial blank shape was optimized to minimize earing in a multi-stage deep drawing process using an artificial neural network(ANN). There has been no reported case of applying artificial neural network technology to the initial blank optimal design for a square case with large aspect ratio. The training data for ANN were obtained though simulation, and the model reliability was verified by performing comparative study with regression model using random sample test and goodness-of-fit test. Finally, the optimal design of the initial blank shape was performed through the verified ANN model.

• 한국산학기술학회논문지
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• 제18권6호
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• pp.330-335
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• 2017

최근 자동차 산업에서 전기 모터 연료 전지에 대한 수요가 급증했으며, 연료 전지 케이스로 사용되는 사각형 알루미늄 캔에 대한 수요 또한 증가하고 있다. 직사각형 배터리 케이스의 바닥에 있는 에어 벤트는 비정상적으로 높은 압력이 발생할 때 미리 압력을 방출하여 큰 폭발을 방지하는 역할을 한다. 직사각형 컵 배터리 케이스는 6 단계의 다단계 딥 드로잉으로 외형을 만들고 직사각형 배터리 케이스와 용접하여 벤트 부품을 제작해왔다. 그러나 본 연구에서는 직사각형 케이스의 바닥면에 공기 벤트 형상을 직접 추가 하는 연구를 수행하였다. 단조의 초기 형상으로는 사각 컵 다단식 딥 드로잉 성형 해석에서 추출한 두께와 형상을 이용한 유한 요소 해석 기법을 사용 하였다. 그 결과, 예측 정밀도가 향상되고, 배부름 및 파단 등의 결함을 미리 예측할 수 있었다. 초기 분석 결과를 토대로 두 가지 단조 형상이 후보로 제시되었고 성형 해석을 통해 최적의 단조 형상을 결정 하였다. 이러한 결과를 바탕으로 금형을 제작하고 실제 결과와 분석 결과를 비교하여 본 연구의 타당성을 검증하였다.

• 한국자동차공학회논문집
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• 제20권3호
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• pp.98-105
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• 2012

Recently, most of the countries started to regulate the emission of vehicle because of the global warming. The engine scooter is also one of the factor which cause the pollution. The hybrid system of a vehicle has many advantages such as fuel saving and emission reduction. The purpose of this study is to choose optimal size of engine, motor and battery for hybrid scooter system using Dynamic programming. The dynamic programming is an effective method to find an optimal solution for the complicated nonlinear system, which contains various constraints of control variables. The power source size of hybrid scooter was chosen through the backward simulator using dynamic programming. From the analysis, we choose the optimal size of each power source. To verify the optimal size of the power source, the Forward simulation was carried out. As a result, the fuel efficiency of hybrid scooter has significantly increased in comparison with that of engine scooter.