• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.476-477
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• 2014

본 논문에서는 넓은 충전전압 범위를 갖는 전기자동차용 급속충전기를 개발하였다. 고효율을 달성하기 위해 AC/DC 컨버터 및 DC/DC 컨버터 모두 3레벨 방식을 적용하였으며 DC/DC 컨버터에 하이브리드 스위칭 기법을 적용하여 넓은 출력전압범위에서 높은 효율을 유지한다. 50kW 시작품을 통해 타당성을 검증하였으며, AC/DC 컨버터 및 DC/DC 컨버터의 정격부하 효율은 각각 98.2%, 97.1%이며 최고효율은 98.6%, 97.1%를 달성하였고, 전체시스템의 정격부하 효율은 95.3%를 달성하였다.

• The KSFM Journal of Fluid Machinery
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• v.15 no.3
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• pp.32-38
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• 2012

This paper is aimed to propose the design database(DB) of the inline micro-turbine for 5kW class. CFD analysis is performed to investigate the effect of a turbine on each parameter. This study showed that RadhaKrishna's data is different from the 5kW class in the low-head and the micro-turbine. Therefore, new DB for the design of inline micro-turbine for 5kW class could be needed. This study configured new design DB for the design of inline micro-turbine for 5kW class. The DB of this study showed that the optimal hub ratio(Dp/DR), the optimal body ratio(Db/DR) and the optimal range of body length ratio(Lh/DR) is 50%, 1.1 and 2.3 to 2.9, respectively.

• 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 KIPE Conference
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• 2018.07a
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• pp.352-353
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• 2018

본 논문은 250kW급 에너지저장장치(ESS)를 이용한 배전계통 일체형 전력변환 장치의 병렬운전 및 부분운전 방식을 제안한다. 제안하는 ESS의 기능은 배전선로에 4식 PCS로 1MW급 계통 연계형 병렬운전, 4식의 ESS 중 1식 이상의 고장에 대해서 모든 ESS가 정지하는 것이 아닌 고장 시료만 정지하는 부분 운전 방식의 운영 사례에 대한 고찰이다. 나아가 병렬운전과 부분운전으로 수용가 부문에서 상업 가정 전력 최적소비 방안을 도출한다. 제안하는 구조는 DC Link를 공유하지 않는 일체형 모형으로 내부 순환전류 회피 가능하다. 본 구조는 시뮬레이션, Prototype, 현장 시험으로 기 성능을 검증하였다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.11 s.254
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• pp.1117-1122
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• 2006

The PEM type regenerative fuel cell(RFC) for the ground simulator of the regeneration electric power system has been designed, manufactured, and tested. In this paper, the designing and manufacturing procedures of the RFC were presented. Also, the performance test results were showed briefly. The RFC consists of PEM type stack, humidifier, pressure and flow control valve, storage tanks, pump and controller. The performance tests were carried out with stack and system performance tests. The performance targets are more than 50% stack efficiency, 1.5kW stack power, less 400W parasitic power in design condition. Most of the performances required are satisfied.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.4
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• pp.356-362
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• 2007

The optimum design and the performance analysis software called POSEIDON for the HAWT (Horizontal Axis Wind Turbine) was developed by use of BEMT. The Prandtl's tip loss theory was adopted to consider the blade tip loss. The aerodynamic characteristics of NACA 63-415 airfoils were predicted via X-FOIL and the post stall characteristics were estimated by the Viterna's equations. All the predicted aerodynamic characteristics are fairly well agreed with the Velux wind tunnel test results. The rated power of the testing rotor is 1 kW at design conditions. The power, estimated by use of predicted lift and drag coefficient via X-FOIL becomes a little higher than experimental one.

• The KSFM Journal of Fluid Machinery
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• v.13 no.4
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• pp.51-57
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• 2010

This paper describes the structural design and testing for 1.5kW class wind turbine composite blade. In order to calculate the equivalent material properties rule-of-mixture is applied. Lay-up sequence, ply thickness and ply angle are designed to satisfy the requirements for structural integrity. Structural analysis by using commercial software ABAQUS is performed to assess the static, buckling and vibration response. And to verify the structural analysis and design, the full scale structural test in flapwise direction was performed under single point loading according to loading conditions calculated by the aerodynamic analysis and Case H (Parked wind loading) in IEC 61400-2.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.1
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• pp.44-52
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• 2017

This paper describes a 100 kW high-efficiency isolated DC-DC converter for DC distribution system. The DC-DC converter consists of two dual-active-bridge (DAB) converters in parallel. The operating principle of the DAB converter is explained, and the algorithm for parallel operation of the DAB converters is proposed. Simulation and experiments are conducted to verify the performance of the proposed system. Experimental results demonstrate that the developed converter excellently marks 97.4 percent of peak efficiency under its normal operating condition.

• Proceedings of the KIPE Conference
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• 2009.11a
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• pp.149-151
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• 2009

본 연구는 다른 에너지원에 비해 출력전류가 커짐에 전압의 드랍이 심한 에너지원을 대상으로하며, 기존의 고효율특성을 갖는 공진형 컨버터가 듀티의 변화에 자유롭지못한 단점을 보안하기위해 캐패시터를 이용하여 기존의 공진형 Push-Pull 컨버터와 부분전압제어가 가능한 Boost컨버터 2대를 결합하여 입력전압의 변화에도 일정한 DClink전압이 형성되도록 하고 있다. 각각 컨버터의 출력전압은 입력전압에 따라 변동하지만 고효율을 위하여 공진형 컨버터부에서 전압할당이 크도록 구성 되었으며, 본 논문은 공진형 Push-Pull컨버터, Boost 컨버터의 동작원리 및 2대의 컨버터를 결합구성 할 경우의 전력의 분담 및 전체적인 제어원리를 다루며, 시뮬레이션을 통하여 이를 입증하고자 한다.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.231-234
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• 2004

This paper is to research about design and drive system of a switched reluctance motor for a pallet truck application. SRM is suitable for a pulse type source and is researched for home and industrial applications owing to the advance of power electronics technology. An SRM for a pallet truck drive is developed and tested. The drive system has to operate with low voltage and high current. The small size, robustness and high efficiency make it possible to replace with DC motor which is used in a pallet truck conventionally. Test results show that pallet truck with SRM has better drive characteristics than that of the DC motor.