• Journal of international Conference on Electrical Machines and Systems
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• 제2권2호
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• pp.171-178
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• 2013

This paper discusses to conduct experimental verification of two types of micro electric vehicles (EV) in order to realize improvement in electric mileage and shorten a charging time of the battery. First, electric double layer capacitor (EDLC) systems to use as a secondary battery are proposed. The internal resistance of EDLC is small compared with a rechargeable battery, and it is suitable for momentary charge-discharge of EV. Next, control circuits of the capacitors to increase the regenerative electric power are utilized. Then, a novel method to charge a main battery of the EV is introduced. Finally, experimental results demonstrate the validity of the proposed method.

• 전기화학회지
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• 제4권4호
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• pp.152-159
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• 2001

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.

• 전력전자학회논문지
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• 제20권5호
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• pp.479-490
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• 2015

The conventional phase-shifted full-bridge (PSFB) converter with an LC filter has been widely used for high-power applications of over 1.0 kW. However, the PSFB converter cannot obtain optimal power conversion efficiency during the battery charging in electric vehicle (EV) on-board battery charger applications because of its unique drawbacks, such as a large circulating current and very high voltage stress in the rectifier diodes. As a result, the converters with a capacitive filter, such as LLC resonant converters, replace the PSFB converter in the EV chargers. This study analyzes the problems of the PSFB converter for EV on-board charger applications in detail. Moreover, the newest converters based on the conventional PSFB converter are reviewed. On the basis of the reviews, new PSFB converter topologies are proposed for EV charger applications. The new topologies are formed by connecting the rectifier stage in the PSFB converter with the output of an LLC resonant converter in series. Many problems of the conventional PSFB converter for EV charger applications can be solved and the performance can be more improved because of this structure; this idea is confirmed by an experiment consisting of prototype battery chargers under the output voltage range of 250-450 Vdc at 3.3 kW.

• Journal of electromagnetic engineering and science
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• 제11권3호
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• pp.174-182
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• 2011

The On-line Electric Vehicle (OLEV) is an electric transport system in which the vehicle's power is transferred wirelessly from power lines underneath the surface of the road. Advantages of the OLEV include reducing battery size and cost to about 20 percent of that of conventional battery-powered electric vehicles, thereby minimizing the vehicle's weight and price, as well as the cost of charging the system. In this paper, we introduce a wireless power transfer mechanism to maximize the electrical performance of the power transfer system. Power transfer capacity, power transfer efficiency, and magnitude of leakage in the electromagnetic field (EMF) are analyzed, and the optimization methodology of the design parameters is discussed.

• 전력전자학회논문지
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• 제9권4호
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• pp.319-325
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• 2004

무공해 자동차를 만들기 위해 중요한 요소로서는 주행거리와 알맞은 가격이다. 니켈-수소 배터리와 같은 향상된 배터리의 개발은 부분적으로 문제를 해결할 수 있으며, 또 하나의 효과적인 방법은 배터리 관리 시스템이나. 니켈-수소 배터리와 배터리 ECU는 주행거리, 가속도, 등판능력과 같은 무공해 자동차의 성능에 영향을 미치는 중요한 구성품이다. 예컨대 운행 중 쉽게 발생하는 단락, 과방전, 과충전은 배터리와 관계되는 가장 큰 문제점이기 때문에 전용의 HEV용 배터리 ECU의 개발은 필수적이다. 본 논문에서는 배터리 전류적산 및 전압에 기초한 HEV용 SOC 알고리즘을 제안하고 배터리 ECU를 설계 및 해석하였으며, 시험을 통해 타당성을 검증하였다.

• Journal of Electrical Engineering and Technology
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• 제8권4호
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• pp.920-929
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• 2013

Within the project 'e performance' supported by the German Ministry of Education and Research (BMBF) an electric vehicle, powered by two lithium-ion battery packs of different capacity and voltage has been developed. The required Energy Management System (EMS) in this system controls the current flows of both packs independently by means of two individual dc-dc converters. It acts as an intermediary between energy storage (battery management systems-BMS) and the drivetrain controller on the vehicle control unit (VCU) as well as the on-board charger. This paper describes the most important tasks of the EMS and its interfaces to the BMS and the VCU. To validate the algorithms before integrating them into the vehicle prototype, a detailed Matlab / Simulink-model was created in the project. Test procedures and results from the simulation as well as experiences and comparisons from the real car are presented at the end.

• 한국환경과학회지
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• 제33권7호
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• pp.523-532
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• 2024

In popular tourist destinations such as Jeju and Gangwon, electric rental cars are increasingly adopted. However, sudden battery drain due to weather conditions can pose safety issues. To address this, we developed a battery consumption analysis model that considers resistive energy factors such as acceleration, rolling resistance, and aerodynamic drag. Focusing on the effects of ambient temperature and wind speed, the model's performance was evaluated during an empirical validation period from November to December 2023. Comparing predicted and actual state of charge (SoC) across different routes identified ambient temperature, wind speed, and driving time as major sources of error. The mean absolute error (MAE) increased with lower temperatures due to reduced battery efficiency. Higher wind speeds on routes 1 and 6 resulted in larger errors, indicating the model's limitation in considering only tailwinds for aerodynamic drag calculations. Additionally, longer driving times led to higher actual SoC than predicted, suggesting the need to account for varying driver habits influenced by road conditions. Our model, providing more accurate SoC predictions to prevent battery depletion incidents, shows high potential for application in navigation apps for electric vehicle users in tourist areas. Future research should endeavor to the model by including wind direction, HVAC system usage, and braking frequency to improve prediction accuracy further.

• 자동차안전학회지
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• 제14권1호
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• pp.55-61
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• 2022

Along with global environmental issues, the size of the electric vehicle market has recently skyrocketed. Various efforts have been made to extend mileage, one of the biggest problems of the electric vehicles, and development of batteries with high energy densities has led to exponential growth in mileage and performance. However, proper thermal management is essential because these high-performance batteries are affected by continuous heat generation and can cause fires due to thermal runaway phenomena. Therefore, thermal management of the battery is studied through the optimal design of the guide vanes, while utilizing the existing battery casing to ensure the safety of the electric vehicles. A battery from T-company, one of a manufacturer of the electric vehicles, was used for the research, and the commercial CFD software, ANSYS CFX V20.2, was used for analysis. The guide vanes were derived through optimal design based on a genetic algorithm with flow analysis. The optimized guide vanes show improved heat removal performance.

• 한국분무공학회지
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• 제28권2호
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• pp.62-67
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• 2023

Recently, the global automobile industry is aiming for a transition from internal combustion locomotives to zero-emission vehicles. Electric vehicles powered by battery energy can operate at peak performance and improve fuel economy by applying multiple motors or multi-speed transmissions. In order to design a two-speed transmission, it is necessary to evaluate and analyze the application system and performance of electric vehicles. In this study, control performance optimization of a twostage battery electric vehicle equipped with an AMT-based automatic transmission was performed and performance according to control pattern changes was analyzed. In order to improve the operating efficiency of the motor, the shift control that sets the optimal operating point according to the vehicle speed and required torque was derived from the motor efficiency map. The performance of battery energy consumption and transmission loss energy according to the hysteresis interval was analyzed and optimized. The hysteresis interval applied to the optimal shift map acted as a factor in reducing the frequency and loss of shifts. It has been shown that keeping the hysteresis interval at about 4 km/h can reduce energy consumption while reducing the number of shifts.

• 항공우주시스템공학회지
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• 제8권4호
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• pp.1-6
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• 2014

This paper presents the trade-off study of conducting a survey of the weights for various kind of propulsion systems installed in the Smart Unmanned Aerial Vehicle TR-100, a tilt-rotor vehicle, which is developed by Korea Aerospace Research Institute, in order to predict the appropriate propulsion system for present and future Personal Air Vehicle, which has single mode and vertical take-off & landing. In order to perform the trade-off study, we set the requirements that the vehicle hovers for 1 hour with 1,000 kg maximum take off weights. In this study, the power systems are classified engine, which uses the fossil fuel - turboshaft engine, piston engine, diesel engine and rotary engine, and electric motor with fuelcell or Li-Ion battery. The results of trade-off study shows the power systems using fossil fuel are superior to using fuelcell or Li-Ion battery for weight of propulsion system. Also turboshaft engine is the best power system for the aspects of system weight, and the nexts are rotary engine, piston engine, diesel engine, electric motor with Li-Ion battery, and electric motor with fuelcell.