• Journal of the Semiconductor & Display Technology
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• v.23 no.3
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• pp.76-84
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• 2024

This paper proposes a method of improving cooling efficiency by applying a Peltier Element to a heat pipe of an air-cooled cooling system of a Battery Thermal Management System for high-speed cooling of a vehicle battery cell. In addition, when the temperature sensor detects the heat generation of the battery cell, the Peltier Element and cooler can be operated to quickly reduce the temperature of the cell. For optimal thermal management, we built an ATmega128A-based Battery Thermal Management System and used KiCAD tool to model and design the cooling system structure. Finally, the experiment verified the high efficiency improvement of cooling performance by comparing the difference between cooling efficiency and cooling performance at room temperature over time for vehicles adopting the existing air cooling method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2197-2210
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• 2016

Recently, the trend of zero emissions has increased in automotive engineering because of environmental problems and regulations. Therefore, the development of battery electric vehicles (EVs), hybrid/plug-in hybrid electric vehicles (HEVs/PHEVs), and fuel cell electric vehicles (FCEVs) has been mainstreamed. In particular, for light-duty electric vehicles, improvement in electric motor performance is directly linked to driving range and driving performance. In this paper, using an improved design for the interior permanent magnet synchronous motor (IPMSM), the EV driving range for the light-duty EV was extended. In the electromagnetic design process, a 2D finite element method (FEM) was used. Furthermore, to consider mechanical stress, ANSYS Workbench was adopted. To conduct a vehicle simulation, the vehicle was modeled to include an electric motor model, energy storage model, and regenerative braking. From these results, using the advanced vehicle simulator (ADVISOR) based on MATLAB Simulink, a vehicle simulation was performed, and the effects of the improved design were described.

• Journal of the Semiconductor & Display Technology
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• v.16 no.1
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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.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.3
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• pp.139-146
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• 2019

As the number of electric vehicles (EVs) in Jejudo Island increases, the secondary use of EV batteries is becoming increasingly mandatory not only in reducing greenhouse gas emissions but also in promoting resource conservation. For the secondary use of EV batteries, their capacity and performance at the end of automotive service should be evaluated properly. In this study, the battery state information from the on-board diagnostics or OBD2 port was acquired in real time while driving three distinct routes in Jejudo Island, and then the battery operating characteristics were assessed with the driving routes. The route with higher altitude led to higher current output, i.e., higher C-rate, which would reportedly deteriorate state of health (SOH) faster. In addition, the SOH obtained from the battery management system (BMS) of a 2017 Kia Soul EV with a mileage of 55,000 km was 100.2%, which was unexpectedly high. This finding was confirmed by the SOH estimation based on the ratio of the current integral to the change in state of charge. The SOH larger than 100% can be attributed to the rated capacity that was lower than the nominal capacity in EV application. Therefore, considering the driving environment and understanding the SOH estimation process will be beneficial and necessary in evaluating the capacity and performance of retired batteries for post-vehicle applications.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.1
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• pp.26-36
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• 2013

This paper presents a simple and cost-effective stand-alone rapid battery charging system of 30kW for electric vehicles. The proposed system mainly consists of active front-end rectifier of neutral point clamped 3-level type and non-isolated bi-directional dc-dc converter of multi-phase interleaved half-bridge topology. The charging system is designed to operate for both lithium-polymer and lithium-ion batteries. The complete charging sequence is made up of three sub-interval operating modes; pre-charge mode, constant-current mode, and constant-voltage mode. The pre-charge mode employs the stair-case shaped current profile to accomplish shorter charging time while maintaining the reliable operation of the battery. The proposed system is specified to reach the full-charge state within less than 16min for the battery capacity of 8kWh by supplying the charging current of 78A. Owing to the simple and compact power conversion scheme, the proposed solution has superior module-friendly mechanical structure which is absolutely required to realize flexible power expansion capability in a very high-current rapid charging system.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.93-99
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• 2019

Small electric vehicles, such as electric bicycles or electric kickboards, operate with the power charged in a battery mounted in the vehicle, and some of these users use emergency power sockets installed in apartments or public facilities without getting permission. For this reason, the necessity for a simple method to approve the use of power with instant payment system rises for the building managers and small vehicle users as well. In this paper, we propose a technique to charge batteries for small electric vehicles with less than 1 [kW] through a power supply control device installed on the existing 15 [A]. sockets on the common residential properties or public buildings. It also describes the power user authorization algorithm and how to charge fees for the power used. As a result of this research, this paper shows how the user authentication power supply system with the effect of preventing power theft can be realized by creating an environment in which a battery in a small electric vehicle can be easily charged.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.3
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• pp.63-72
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• 2014

The exchangeable battery electric bus is an eco-friendly public transportation vehicle. Due to the technological limitation, however, it should repeatedly change batteries with charged ones. The unmanned battery exchangeable electric bus being studied in Korea can exchange batteries automatically by using a battery swapping system. In this paper, we propose an unmanned battery exchangeable electric bus management system. The proposed system provides two services: the bus information service and the battery change scheduling service. The bus information service is the existing traditional metropolitan area bus information systems, which inform bus passengers how long they should wait for the buses. Our second service assigns a low-battery bus, which needs to change the batteries, to the battery swapping system, which stores fully-charged batteries. To validate the proposed system, we model the system by using the DEVS formalism. The simulation result shows that the proposed system provides the services properly.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.410-413
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• 2004

In this paper, a simulator system for Fuel Cell Hybrid Electric Vehicles(FCHEV) is implemented using DSP boards with CAN bus. The subsystems of a FCHEV i.e., the fuel cell system, the battery system, the vehicle dynamics with the transmission mechanism are coded into 3 DSP boards. The power distribution control algorithm and battery SOC control are also coded into a DSP board. The real-time monitoring program is also developed to examine the control performance of power control and SOC control algorithms.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.195-200
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• 2003

An electric vehicle uses the system to a power source whether it limps a high efficiency, without environmental pollution It coincides the best at the 21th century environmental regulation and energy frugality. The motor control system using DC-DC converter is carried out in this study. The Present control system is structured the better condition than that of the AC-DC converter with DC-AC inverter. Further, a vehicle dynamics analysis is peformed for the case of Mini-Baja it is found that the analysis dynamic system for the Mini-Baja gives a good design parameters.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.456-465
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• 2019

PHEV(Plug in Hybrid Electric Vehicle) and BEV(Battery Electric Vehicle) equip high voltage batteries to drive motor and vehicle electric system. Those vehicle require OBC(On-Board Charger) for charging batteries and LDC(Low DC/DC Converter) for converting from high voltage to low voltage. Since the charger and the converter actually separate each other in electrical vehicles, there is a margin to reduce the vehicle weight and area of installation by integration two systems. This paper studies a 1.5kW LDC converter that can be integrated into an OBC using an isolated current-fed converter by simplifying the design of LDC transformers. The proposed LDC can control the final output voltage of the LDC by using a fixed arbitrary output voltage of the bidirectional buck-boost converter, so that Compared to the existing OBC-LDC integrated system, it has the advantage of simplifying the transformer design considering the battery voltage range, converter duty ratio and OBC output turn ratio. Prototype of the proposed LDC was made to confirm normal operation at 200V ~ 400V input voltage and maximum efficiency of 91.885% was achieved at rated load condition. In addition, the OBC-LDC integrated system achieved a volume of about 6.51L and reduced the space by 15.6% compared to the existing independent system.