• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.885-886
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• 2006

We have proposed a 100 MVA, 3 phases, 154 kV class HTS transformer which will substitute for 60 MVA conventional transformer. In this paper, we designed conceptually the structure of the superconducting windings of a single phase 33 MVA transformer. The power transformer of 154 kV class has a tertiary winding besides primary and secondary windings. So the HTS transformer should have the 3rd superconducting winding, it makes the cost of the HTS transformer high and the efficiency low. Further more we considered On Load Tap Changer (OLTC) in HTS power transformer. OLTC equipment is required for fitting to a power transformer by which the voltage ratio between the windings can be varied while the transformer is on load. We analyzed the electrical characteristics of the HTS transformer such as magnetic stress and AC loss.

• 한국산업경영시스템학회:학술대회논문집
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• 한국산업경영시스템학회 2002년도 춘계학술대회
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• pp.19-24
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• 2002

The result of management profits create to manufacturing activity. The gross sale profits must be maximum thraw spend of economic value. The profit maximum have to management based key value driver of manufacturing activity. The important factors of the study model are manufacturing value driver(MVD) and manufacturing value added(MVA). We show necessity of management based value by means of a case study.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.506-507
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• 2011

본 논문에서는 신재생에너지의 에너지 백업용으로 사용되어지는 2MVA BESS(Battery Energy Storage System)의 수냉형 PCU(Power Conditioning Unit)을 설계하고 3D 모델링 및 열해석을 통해 열적 안정성을 확인하고 이를 실험으로서 검증한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.674_675
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• 2009

수치해석을 사용하여 2MVA 몰드 변압기의 정전용량을 시뮬레이션(FLUX 2D)하고 계산하였다. 산출한 정전 용량 값을 변압기 모델링 회로에 적용하여 switching surge 등 이상전압이 인가되었을 때 변압기 내부에 있는 권선들의 전압분포를 예상하고 절연설계에 적용 할 수 있음을 보였다.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.41-44
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• 2003

We manufactured double pancake type windings with BSCCO wire for 1MVA HTS transformer. To verify cracks of HTS wire and performance of manufactured windings, the transportation current was measured. In this paper, we present result of the transportation current test as a DC current and compare a drop of current performance of HTS wire due to tension and rounding during the manufacturing with technical data. We obtained good results and this will be useful for another manufacturing of HTS winding

• 산업경영시스템학회지
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• 제19권40호
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• pp.263-269
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• 1996

The most vital arc in the maximum flow problem is that arc whose removal results in the greatest reduction in the value of the maximal flow between a source node and a sink node. This paper develops an algorithm to determine such a most vital arc(MVA) in the maximum flow problem. We first define the transformed network corresponding In a given network in order to compute the minimal capacity for each candidate arc. The set of candidate arcs for a MVA consists of the arcs whose flow is at least as greate as the flow over every arc in a minimal cut As a result, we present a method in which the MVA is determined more easily by computing the minimal capacity in the transformed network. The proposed method is demonstrated by numerical example.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
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• pp.98-100
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• 2008

This study proposes a model of 1.5MVA wind power system in Go-chang field demonstration and performs simulation according to variable wind speed. 1.5MVA wind power system was verified by computer simulations with PSCAD/EMTDC software. Terminal voltage, grid voltage and active/reactive power can be observed through the simulation results.

• Journal of the Optical Society of Korea
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• 제18권6호
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• pp.783-787
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• 2014

This paper presents an improved vertical alignment nematic liquid crystal mode characterized by the protrusions or slits of the top substrate and additional stripe type common electrodes with polarity switching of the bottom substrate to improve multi-domain vertically aligned (MVA) and patterned vertically aligned (PVA) nematic modes. MVA and PVA modes have disadvantages such as an LC disclination in the vicinity of the middle region of electrodes between the top and bottom protrusions in MVA mode or the top and bottom slits in PVA mode. Therefore, the stripe type common electrode generating a horizontal electric field and the protrusion or slit producing some pretilt of liquid crystals (LCs) were used to improve the LC disclination, which influences the transmittance and response speed. The simulation results showed that the proposed VA mode has higher transmittance than the MVA and PVA modes. As a result, the proposed VA mode can improve the response speed and transmittance remarkably, which makes it useful for upgrading the LCD display quality.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1645-1648
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• 2008

We successfully fabricated lowest-cost superior perform ance MVA LCDs with highest-yield, high transmission, high contrast-ratio, and wide viewing angle. Using the amplified intrinsic fringe field (AIFF) controlled MVA invented by Ong, we eliminated all protrusions and ITO slit geometries. We further achieved: (1) faster gray-gray response times without the over-drive technology, (2) faster tough mura, and (3) lower flicker and cross-talk in the row inversion driving schemes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.363-364
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• 2008

한전 전력연구원이 주관하고 (주)효성이 참여하는 협동 연구의 형태로 진행된 연구과제의 결과물로써 100MVA급 STATCOM에 사용될 인버터 폴이 설계, 제작되었다. 100MVA STATCOM 인버터 폴은 순수 국내 기술로 설계, 제작되었으며, (주)효성 안양공장 H-Bridge 시험장에서 전압, 전류 시험 및 Heatrun 시험을 완료 하였다. 본 논문에서는 100MVA STATCOM 인버터 폴의 시스템 구성, 시험방법 및 실증시험에 대하여 정리하였다.