• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.84.2-84.2
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• 2015

Growing market of electric vehicles such as hybrid, plug-in hybrid, and bare electric vehicles in the world is accelerating the significance of Li-ion batteries as a renewable green energy. According to such market flow, the developing components such as cathode, anode, electrolyte, and separator, composing the Li-ion batteries, is significantly important tasks for the commercialization. In particular, development of the cathode material having high capacity and stable thermal stability is essential for long-distance electric vehicle in the near future. Herein we introduce various applications of Li-ion batteries such as portable electronics, electric vehicles, and energy storage system, and also its research trend, in particular on the cathode materials.

• Journal of electromagnetic engineering and science
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• v.15 no.3
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• pp.129-133
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• 2015

This paper presents the dosimetry of a resonance-based wireless power transfer (RBWPT) system for electric vehicles applications. The compact RBWPT system is designed to transfer power at 150-mm distance. The electric and magnetic fields generated by the RBWPT system and the specific absorption rate in the human body model, which stands around the system, are calculated. These analyses are conducted in two cases: the alignment and the misalignment between the transmitter and the receiver. The matching loops are adjusted to maximize the power transfer efficiency of the RBWPT system for the misalignment condition. When the two cases were compared for the best power transfer efficiency, the specific absorption rates (SAR) in the misalignment case were larger than those in the alignment case. The dosimetric results are discussed in relation to the international safety guidelines.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.3
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• pp.269-274
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• 2013

Fault-tolerant capability, wide speed range and overload capability are required in electric motors used in electric vehicles. In this paper, based on the analysis of the all poles wound and alternate poles wound flux-switching permanent-magnet machines, an optimization method is studied to reduce torque ripple. The method takes account of both flux-leakage and cogging torque. The simulation result shows that the method can reduce the torque ripple effectively. This study lays the foundation for the further application of FSPM in electric vehicles.

• Corrosion Science and Technology
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• v.18 no.4
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• pp.117-120
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• 2019

Considering the tendency of development of electrification vehicles, development and verification of new evaluation technology is needed because of new technology applications. Recently, as the battery package is set outdoors of an electric vehicle, such vehicles are exposed to corrosive environments. Among major components connected to the battery package, rust prevention of high-voltage cables and connectors is considered the most important issue. For example, if corrosion of high voltage cable connectors occurs, the corrosion durability assessment of using an electric vehicle will be different from general environmental corrosion phenomena. The purpose of this study is to investigate the corrosion mechanism of high voltage cable connectors of an electric vehicle under various driving environments (road surface vibration, corrosion environment, current conduction by stray current, etc.) and develop an optimal rust prevention solution. To improve our parts test method, we have proposed a realistic test method to reproduce actual electric vehicle corrosion issues based on the principle test.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.1
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• pp.103-110
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• 2017

Most commercial vehicles have adopted the hydraulic power steering system. To reduce fuel consumption and to improve steering controllability, a hybrid electric power steering system is being developed for commercial vehicles. In this study, the HILS (Hardware In the Loop Simulation) system equipped with a commercial vehicle hybrid electric power steering system was developed and the vehicle dynamic performance of a truck with the steering system was evaluated. The hybrid electric power steering system is composed of the EHPS motor pump, column mounted EPS system, and ball nut steering gear box for heavy commercial vehicles. The accuracy of vehicle models equipped with the HILS system was verified with comparisons between the simulation results and field test results. The road reaction forces of the steering system were generated from the vehicle model and verified using field test results. Step steering tests using the verified HILS system were carried out and the performance of a newly developed commercial vehicle hybrid electric power steering system was evaluated.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.255-260
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• 2021

The importance of electric vehicles is gradually increasing due to the recent depletion of fossil fuels. In order to use an electric vehicle, the battery built into the vehicle must be frequently charged. Electric vehicles has very good performance in terms of noise and vibration. However, due to the limitations of the battery, the mileage is considerably shorter than that of an internal combustion engine vehicle once it is charged, and the battery charging time is relatively long compared to the refueling time. There are two types of charging methods for electric vehicle batteries: plug-in and wireless charging. In this paper, we introduced the wireless charging technology for electric vehicles and the current state of technology development and standards in major countries.

• Smart Media Journal
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• v.9 no.1
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• pp.67-74
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• 2020

As the demand of electric vehicles has been increased recently, their related industries are developing. In particular, the market of electric vehicles charging infrastructure is expanding rapidly and users have much demand in convenience of electric vehicles charging site. Because an charging site using electric pole of KEPCO can make use of that installed nearby public parking lots, there are many commercial construction and convenient facilities near around it. In this situation, users can do shopping or their personal business during charging. In this paper, we proposed the design of charging platform for electric vehicles to support LBS for users to do shopping or personal business conveniently.

• Journal of Climate Change Research
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• v.8 no.3
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• pp.265-273
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• 2017

Recently the Paris Climate Change Accord has been officially put into effect, making global efforts to implement Greenhouse Gas (GHG) reductions, and also International environmental regulations in the automotive sector will be further strengthened. The electric vehicle, which minimizes the particulate matter generated by existing internal combustion engine automobiles, is evaluated as a representative eco-friendly automobile. However, charging the battery of an electric vehicle is not fully environment-friendly if it is fueled by electricity that is being generated by fossil fuels as an energy source. The energy generated by the photovoltaic power generation system, which is an infinite clean energy, can be used to charge an electric vehicle's battery. Currently, shortage of charging facilities, time of charging, and high battery prices are the problem of activating the supply of electric vehicles. This study is to build a conjunction between the EVBSS (Electric Vehicle Battery Supply System) and ESS (Energy Storage System), which can quickly supply the photovoltaic charged battery to the required demand. If the charged battery in the Battery Swapping Station (BSS) is swapped swiftly, it will dramatically shorten the waiting time for charging the battery. As a result, if the battery is rented when it is needed, electric vehicles can be sold without the cost of a battery, which accounts for a large portion of the total cost, then the supply of electric vehicles are expected to expand. Furthermore, it will be an important alternative to maneuver climate change by minimizing GHG emissions from internal combustion engine vehicles.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.1
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• pp.15-20
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• 2020

• Journal of Power Electronics
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• v.17 no.2
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• pp.334-345
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• 2017

In order to meet the increasing needs of the hybrid energy source system for electric vehicles, which demand bidirectional power flow capability with a wide-voltage-conversion range, a bidirectional three-level DC-DC converter and some control strategies for hybrid energy source electric vehicles are proposed. The proposed topology is synthesized from Buck and Boost three-level DC-DC topologies with a high voltage-gain and non-extreme duty cycles, and the bidirectional operation principle is analyzed. In addition, the inductor current ripple can be effectively reduced within the permitted duty cycle range by the coordinated control between the current fluctuation reduction and the non-extreme duty cycles. Furthermore, benefitting from duty cycle disturbance control, series-connected capacitor voltages can also be well balanced, even with the discrepant rise and fall time of power switches and the somewhat unequal capacitances of series-connected capacitors. Finally, experiment results of the bidirectional operations are given to verify the validity and feasibility of the proposed converter and control strategies. It is shown to be suitable for hybrid energy source electric vehicles.