• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1175-1176
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• 2011

Electric Vehicle Supply Equipment(EVSE) is a system or an equipment to supply electric power for charging the traction batteries on the electric vehicle. EVSEs are classified with a conductive charging system and an inductive charging system by the power transfer method. Inductive charging systems are necessary to use high frequency converters to increase the output power and to reduce the size of the charging systems. In this paper, a 20kHz inverter for inductive charging system has been designed and PSCAD/EMTDC have been used to simulate the output characteristics of the 20kHz inverter.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.274-277
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• 1995

Recent environmental pollutions have intensified the need to develop zero emission vehicles. The most effect method of such solutions is EV. EV is high energy efficiency, easy to maintain, repair and is possible to make high performance control. However, because energy density of batteries is constrained and the distance covered one charge is short range. Also because EV has disadvantage of poor accelation ability, development of high performance battery is required for large scale use of EV. EV charger analogous to gas apparatus must also be developed immediately. Charger is discriminate between on-vehicle type and off-vehicle type. As off-vehicle type is able to charge fast and safe, inductive charging is considered. This paper aims to develope off-vehicle inductive charging system. Therefore, it achieved power factor correction converter, high frequency DC/AC inverter control algorithm development which gives proof validity through simulation and formulated the basic concept of high frequency transformer design for inductive charging.

• Journal of the Semiconductor & Display Technology
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• v.23 no.3
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• pp.85-90
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• 2024

Conductive charging of electric vehicles has entered a stable stage, and various product lines have been developed and standards have been made. Inductive charging methods can be classified into various other methods such as Indirect Power Transfer, Coupled Magnetic Resonance, and Permanent Magnet Coupled Transfer. Since choosing the most effective charging method for electric vehicles is difficult, standardizing the method of wirelessly transferring power is still a challenge to be achieved in a future. SAE J2954 sets an overall standard of electric vehicle Wireless Power Transport system. This paper proposes a wireless charging module that installs two receiving coils at a certain distance under the vehicle to minimize coil alignment due to incorrect parking and other vehicle full length during static charging. Finally, we developed an ATmega128 MCU-based module prototype and tested it to verify the efficiency of lower misalignment probability in different alignment charging environments compared to conventional single VA coils.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.2
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• pp.196-200
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• 2013

In this paper, the design of PRT vehicle power supply system is discussed. Since there is no power feeding line facilities in PRT system under development, the PRT vehicle must have its own energy storage device on board. For the energy storage device, ultra-capacitor bank is applied due to its fast charging capability and long life time. Charging the Ultra-capacitor bank is performed by wireless inductive power transfer system. The capacitor bank is charged up in less than 10 seconds when the vehicle is traveling by passenger stations. In this paper the design of the ultra-capacitor bank and the wireless inductive power transfer system for the PRT vehicle are discussed. Tests are conducted for the both system and the result shows the efficiency of the wireless inductive power transfer system is higher than 80%.

• Journal of IKEEE
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• v.23 no.1
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• pp.306-309
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• 2019

Wireless charging is a technology of transmitting power through an air gap to an electrical load for the purpose of energy dissemination. Compared to traditional charging with code, wireless power charging has many benefits of avoiding the hassle from connecting cables, rendering the design and fabrication of much smaller devices without the attachment of batteries, providing flexibility for devices, and enhancing energy efficiency, etc. A transmitting coil and a receiving coil for inductive coupling or magnetic resonant coupling methods are available for the near field techniques, but are not for the far field one. In this paper, the wireless power transfer (WPT) circuit by using magnetic resonant coupling method with a resonant frequency of 13.45 Mhz for the low power system is implemented to measure the power transmission efficiency in terms of mutual distance and omnidirectional angles of receiver.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1855-1860
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• 2010

Electric vehicles have reached a new level of development with introductions by Chrysler, Ford, Honda and Toyota. Today's charging technology includes conductive and inductive charging systems. There are three standardized charging levels: Level 1: charging can be done from a standard, grounded AC 120V, 3-prong outlet available in all homes; Level 2: charging is at AC 240V, 40 amp charging station with special consumer features to make it easy and convenient to plug in and charge EVs at home or at an EV charging station; Level 3: a high-powered charging "fast charge" technology currently under development that will provide a charge in less than 15 minutes. The incoming AC power is converted to DC and stored in the vehicle's batteries. In this paper, we investigated the application of urban railway DC electric power for electric car charging system.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.3
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• pp.237-246
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• 2022

This paper proposes a method to adjust the turn ratio of a transformer for the high-efficiency operation of an LLC converter with a wide input range in a wired/wireless integrated charging system for electric vehicles. The characteristics of the inductive power transfer converter in the integrated charging system are analyzed to design the LLC converter, and the DC-link voltage range is derived. The aspect of voltage gain following each parameter of the LLC converter is analyzed, and the resonant network and transformer are designed. Based on the designed parameters, the feasibility of the design and control method is verified by implementing the operation of the LLC converter according to the DC-link and battery voltages.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.1886-1891
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• 1998

Traction battery chargers are an integral part of the required charging infrastructure. EV charging systems are continuing to improve in design. The newer types are affecting power quality to a much lesser extent. High efficiency battery chargers are being designed and produced which form little or no harmonic distortion. In addition chargers are becoming smaller and lighter. This is due mainly to the fact that there are improvements in the power electronics industry, especially with respected to IGBTs. Lower costs are achieved by the reduction in price of the IGBTs, standard magnetic material and small cores for inductors and transformers. But electric vehicles occupy a relatively small market niche at present. Therefore with already existing power supply networks, establishment of EV infrastructure can safeguard the service value of present vehicle as well as ensure the ability to charge a significant number of such vehicle. In this paper, we surveyed the update charging technologies according to the conductive charging, inductive charging and fast charging. Then we suggested cost-optimized charging infrastructure in consideration of the economical, political and technical standpoint.

• Journal of Power Electronics
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• v.18 no.4
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• pp.1278-1292
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• 2018

Inductive power transfer (IPT) technology allows for charging of electric vehicles with security, convenience and efficiency. However, the IPT system performance is mainly affected by the magnetic coupling structure which is largely determined by the coupling coefficient. In order to get this applied to electric vehicle charging systems, the power pads should be able to transmit stronger power and be able to better sustain various forms of deviations in terms of vertical, horizontal direction and center rotation. Thus, a novel cross-shaped magnetic coupling structure for IPT charging systems is proposed. Then an optimal cross-shaped magnetic coupling structure by 3-D finite-element analysis software is obtained. At marking locations with average parking capacity and no electronic device support, a prototype of a 720*720mm cross-shaped pad is made to transmit 5kW power at a 200mm air gap, providing a $1.54m^2$ full-power free charging zone. Finally, the leakage magnetic flux density is measured. It indicates that the proposed cross-shaped pad can meet the requirements of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) according to the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA).

• Journal of Satellite, Information and Communications
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• v.9 no.1
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• pp.90-96
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• 2014

This paper is about increasing transfer efficiency of wireless power transmission. The new method is proposed to detect the alignment of transmitter and receiver of wireless charger and so smart phone can display the position of wireless charging receiver on its LCD panel for the maximum charging efficiency. The previous method is only to show the transfer efficiency, but this method is to show not only the efficiency but also coordinates of receiver. The apparatus of the wireless charger is based on WPC(Wireless Power Consortium) standard and has planar air coil combined with magnet shield in Tx and Rx device so that the leakage flux is minimized on condition of under hundreds of kHz operating frequency. In this paper, it's showed that relation of magnet field and distance of each coils can be linearized and position information of Tx and Rx device is calculated thru trigonometry. Through the experiment, the obstacles of linearity are discovered and also showed that it can be optimized. and so the presented method is suitable for alignment detection method of Tx and Rx device in WPC wireless charger.