• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.1
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• pp.80-90
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• 2014

This paper suggests loss analysis and calculation methods for efficiency improvement of power conversion equipment in detail. The detailed loss analysis and calculation has been conducted for 3.3kW On-board Battery Charger considering temperature condition. The validity of the analysis and calculation method is verified by simulation model.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.4
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• pp.277-284
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• 2021

A single and three phase-compatible single-stage EV charger without electrolytic capacitor is proposed in this study. DC battery-charging current is inherently guaranteed in the three-phase grid due to three output currents with a phase shift of 120° between each other. The proposed EV charger can provide a DC battery charging current for the single-phase grid through the integrated active power decoupling circuit without using additional switches. The proposed EV charger ensures ZVS turn-on of all switches with wide grid and battery voltage ranges. The 11 kW prototype of the proposed EV charger demonstrates a peak efficiency of 97.01% and a power density of 5.58 kW/L.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.341-342
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• 2010

최근 들어 친환경 자동차 분야는 바야흐로 전기자동차 시대를 맞이하게 되었다. 이러한 전기자동차는 전지(battery)로부터 전력을 공급받아 전동기로 차량을 구동하는 구조로 되어 있어 전지를 충전하기 위한 충전기가 필수적이다. 이러한 충전기는 탑재형 충전기(on board charger)와 별치형 충전기(off board charger)로 분류된다. 보통 별치형 충전기는 급속충전용으로 3상 교류전원을 직류로 변환하여 최대 400A의 용량까지 사용할 수 있다. 본 논문에서는 자동차에 직접 장착되는 탑재형 충전기를 제안한다. 제안된 충전기는 상용전원을 입력으로 넓은 범위의 출력을 갖으며 고효율, 고역률, 고전력밀도의 충전기로 시작품을 제작하여 그 기능을 검증하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.10
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• pp.1499-1504
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• 2013

As oil price and demand for environment friendly vehicle rapidly increase, research on electric car is being widely carried out. Especially, NEV(Neighborhood Electric Vehicle) is a pollution-free vehicle that can be mass-produced which the time of development for related technologies is urgently needed. In this paper the On-Board charger for mid- and large- sized secondary cell is applicable in aerospace and other general industries, and the Off-Board standing charger is expected to be employed in creating charging infrastructure.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.6
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• pp.511-521
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• 2014

This study proposes an electric vehicle (EV) smart panel board and its control method on the basis of charging scheduling. The proposed system consists of batteries, a three-phase battery charger, three single-phase inverters, transfer switches for electric power distribution, and a controller. The three-phase battery charger usually charges the batteries at midnight when electric rates are cheap and in light load. When the electric power consumption of the EV standard chargers connected to one phase of the power line is relatively large or when a blackout occurs, the electric power stored in the battery is supplied by discharging through the inverters to the EV standard chargers. As a result, the value of peak load and the charging electric power quantity supplied from a utility grid are reduced, and the current unbalance is improved. The usefulness of the proposed system is confirmed through simulations, experiments, and case studies.

• Journal of Power Electronics
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• v.15 no.5
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• pp.1158-1167
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• 2015

In this paper, a new hybrid DC-DC converter is proposed for electric vehicle 3.3 kW on-board battery charger applications, which can be modulated in a phase-shift manner under a fixed frequency or frequency variation. By integrating a half-bridge (HB) LLC series resonant converter (SRC) into the conventional phase-shift full-bridge (PSFB) converter with a full-bridge rectifier, the proposed converter has many advantages such as a full soft-switching range without duty-cycle loss, zero-current-switching operation of the rectifier diodes, minimized circulating current, reduced filter inductor size, and better utilization of transformers than other hybrid dc-dc converters. The feasibility of the proposed converter has been verified by experimental results under an output voltage range of 250-420V dc at 3.3 kW.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.27-28
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• 2015

In this paper a high efficiency wireless on-board charger for Electric Vehicle (EV) is proposed and the theoretical analysis based on the two-port network model to come up with suitable design for the battery charge application is presented. The proposed Wireless Power Transfer (WPT) method has adopted four-coil system with air core and its superior performance is proved by comparing it to the conventional two-coil system by the mathematical analysis. In addition, since the proposed WPT converter is able to operate at an almost constant frequency regardless of the load, CC/CV charge of the battery can be simply implemented. A 6.6kW prototype is implemented with 20cm air gap to prove the validity of the proposed method. The experimental results show that the dc to dc conversion efficiency of the proposed system achieves 97.08% at 3.7 kW.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.634-637
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• 2001

The proposed contactless charger employs a pair of neighboring printed circuit board windings as a contactless energy transfer device, thereby making it amenable to low-profile designs and suitable for applications to the portable telecommunication/computing electronics in which stringent requirements for height, space, and reliability have to be met. The performance of the proposed charger is confirmed with experiments on a prototype charger developed for cellular phones.

• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.111-112
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• 2017

This paper presents a novel three-port converter for the OnBoard Charger of Electric Vehicles by using an impedance control network. The proposed concept is suitable for charging a main battery and an auxiliary battery of an electric vehicle at the same time due to its power handling capability of the converter without additional switches. The power flow is managed by the phase angle (${\Theta}$) between the ports whereas voltage at each port is controlled by the asymmetric duty cycle and the phase shift (${\Phi}$) between the inverter lags controlled by the impedance control network. The proposed system has a capability of achieving zero voltage switching (ZVS) and zero current switching (ZCS) at all the switches over the wide range of input voltage, output voltage and output power. The feasibility of the proposed system is verified by the PSIM simulation.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.1
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• pp.40-45
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• 2014

This study examines the system and process of battery stored energy in vehicles and suggest the effective area for the use of V2G(vehicle-to-grid) from Jeju Smart Grid Demonstration Project. V2G means technology of electric power transmission from the battery of electric-drive vehicles to state grid. As for the increasing of effectiveness for demand-side control, V2G is a very good alternative. In the U.S., the utilization of electric vehicles is under 40% on average. In this case, we can use he battery of electric vehicle as role of frequency regulation or generator of demand-side resource. V2G, which is the element of Smart Transportation, consists of electric vehicle battery, BMS(battery management system), OBC(on-board charger), charging infrastructure, NOC(network operating center) and TOC(total operation center). V2G application has been tested for frequency regulation to secure the economical efficiency in the United States. In this case, the battery cycle life is not verified its disadvantage. On the other hand, Demand Response is required by low c-rate of battery in electric vehicle and It can be small impact on the battery cycle life. This paper concludes business area of demand response is more useful than frequency regulation in V2G application of electric vehicles in Korea. This provides the opportunity to create a new business for power grid administrator with VPP(virtual power plant).