• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.1-2
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• 2011

본 논문에서는 D=0.5에서 2배의 승 강압비를 갖는 하이브리드 자동차 HDC용 비절연 양방향 DC-DC 컨버터를 제안한다. 제안한 컨버터는 CCM에서도 소프트스위칭이 가능하며 스위치 전압정격이 1/2로 되어 소자의 선정에 유리하다. 또한 수동소자의 부피도 기존 양방향 컨버터 보다 작아 고효율 및 고전력 밀도를 달성할 수 있다. 제안하는 양방향 컨버터의 최적의 스위칭 기법을 제안하였고 10kW급 축소시작품의 실험을 통해 본 논문의 타당성을 검증하였다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.796-797
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• 2011

하이브리드 자동차의 Integrated Starter & Generator (ISG)는 기동 시 높은 토크를 발생시키면서 진동과 소음을 동반한다. 이러한 진동 및 소음은 차량의 품질 확보를 위하여 최소화 시켜야 할 필요가 있다. 본 논문에서는 매입형 영구자석 동기 전동기로 설계된 ISG의 진동 및 소음 저감에 관한 연구에 대하여 다룬다. ISG의 진동 및 소음 저감을 위하여 회전자 코어의 형상 최적설계, 슬롯 수 변경설계 그리고 회전자의 step skew를 적용시켜 각각의 설계방법이 ISG의 진동 및 소음에 미치는 영향을 해석과 실험을 통해 검증하였다.

• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.75-77
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• 2007

본 논문에서는 엔진, 발전기, 견인 전동기, 배터리, 전력 변환기로 구성된 직렬형 하이브리드 전기 자동차의 최적 효율 운전 및 통합 전력제어에 관해 논의한다. 제안된 시스템의 엔진은 최적 효율 운전을 위해 부하에 따라 가변속(Variable Speed) 운전되며, 속도를 가변하여도 필요한 전력을 순시적으로 제어할 수 있다. 또한 자동차가 요구하는 다양하고 순시적인 전력의 변동에 대응할 뿐만 아니라 엔진의 연료 효율 및 배터리의 수명을 고려하여 엔진과 배터리의 전력을 적절히 분배하여 공급할 수 있는 통합 전력제어 방법에 관해서도 논의한다. 제안된 통합 전력제어 알고리즘의 유용성은 컴퓨터 시뮬레이션을 통해 검증하였다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.4
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• pp.278-287
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• 2009

Plug-in hybrid electric vehicle (PHEV) with capability of being recharged from the power-grid will reduce oil consumption. Also, the PHEV will affect the utility operations by adding additional electricity demand for charging. In this research, the power-grid impact by demand of PHEV charging is presented and the optimal charging control strategy for utility operators is proposed with simulated data. The penetration of PHEV is assumed to be 50% in the circumstances of Korean passenger car market and Korean power-grid market limitedly. To obtain smooth load shape and utilize the surplus electricity in power-grid at midnight and dawn, the peak of charging demand should be controlled to be located before 4:00 a.m., and the time slot which can supply the electricity power to PHEV should be allowed between 1:00 a.m.$\sim$7:00 a.m.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.4
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• pp.555-566
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• 2012

This paper presents a thermal analysis of an interior PM synchronous machine with concentrated winding for electric vehicle. The conventional thermal equivalent network model has been used for a long time for calculation of the temperature rises in electrical machines. In spite of being popular, this method can not be applied correctly for elements with complicated cooling structure like liquid cooled housing. To overcome this drawbacks, in this paper, a hybrid thermal model using the result of CFD analysis partly. Using this method, to improve a thermal performance of PMSM with concentrated winding, the effects of two design parameters are analysed. Finally, the accuracy of this model has been verified by experiments for the developed 21kW motor.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.3
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• pp.8-18
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• 2010

According to the needs of change to hybrid, fuel cell and electric vehicle, and to the increasing demand for safety and eco-friendliness, the necessity of Electro-Mechanical Brake(EMB) is being increased. But, one of the most important problems for realizing EMB to the practical use is that the required motor power for braking is too high. So the high braking efficient EMB is required. In recent years, the Electronic Wedge Brake(EWB) is noticeable for the high braking efficiency. In this research, we examine the improvable matter of the recent published EWB, and we propose the improved mechanism and the cost effective control method using this mechanism. And we test these feasibility by experiment and discuss these meaning and effect.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.325-329
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• 2004

본 논문은 하이브리드 전기자동차의 12V보조배터리 충전용 DC-DC 컨버터의 최적설계에 관한 것으로 하이브리드 전기자동차의 특성상 DC-DC 컨버터는 최대부하의 $30\%\~70\%$ 정도의 비교적 낮은 부하영역에서 주로 동작하므로 이에 따른 적절한 설계가 요구된다. 따라서 DC-DC 컨버터의 주 동작영역에서 효율이 높도록 주요 설계요소인 스위칭 주파수와 고주파 변압기의 누설인덕턴스를 적절히 선정하고 코아의 윈도우 면적을 최소화하는 최적설계에 관한 연구이다.

• Journal of Power Electronics
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• v.9 no.3
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• pp.472-480
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• 2009

In this paper, a charge equalization converter with parallel-connected primary windings of transformers is proposed. The proposed work effectively balances the voltage among Lithium-Ion battery cells despite each battery cell has low voltage gap compared with its state of charge (SOC). The principle of the proposed work is that the equalizing energy from all battery strings moves to the lowest voltage battery through the isolated dc/dc converter controlled by the corresponding solid state relay switch. For this research a prototype of four Lithium-Ion battery cells is optimally designed and implemented, and experimental results show that the proposed method has excellent cell balancing performance.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.801-804
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• 2002

Electrochemical capacitors are becoming attractive energy storage systems particularly for applications involving high power requirements such as hybrid systems consisting of batteries and electrochemical capacitors for electric vehicle propulsion. Both of amorphous cobalt oxide and manganese dioxide were prepared by sol-gel process reported in our previous work. Nanostructured supramolecular oligomer of 1,5-diaminoanthraquinone(DAAQ) coated metal oxides were successfully prepared by electrochemical oxidation from an acidic non-aqueous medium. We established process parameters of the technique for the formation of nano-structured materials. Furthermore, improved the capacitive properties of the nano structured metal oxide electrodes using controlled solution chemistry. $CoO_2$ and $MnO_2$-based composite electrode showed relatively good electrochemical behaviors in acidic electrolyte system with respect to specific capacity and scan rate dependency.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.505-507
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• 2005

In this paper, a timing analysis is performed for the CAN-based simulator system for a fuel cell hybrid electric vehicles. The CAN protocol is recently being used for conventional vehicles, however, the network-induced delay can make the in-vehicle network system unstable. This problem may be occurred in the future vehicles because more ECUs are being required than recent vehicles. In order to develop a stable network-based control system, timing analysis is required at the design process. Throughout this analysis, timing parameters that affect transmission delay are examined and an effective method of predicting a sampling time for a stable communication via CAN protocol. In order to show the validityof suggested timing analysis. some experiments are performed using DSPs with CAN module.