• Aerospace Engineering and Technology
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• v.9 no.2
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• pp.63-72
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• 2010

MOV(Main Oxidizer shut-off Valves) control the combustion of launch vehicle systems by the supply and the isolation of liquid oxygen to a main combustion chamber in launch vehicle systems. Moreover, the MOV should secure a constant flow rate of liquid oxygen for combustion instability in the steady operational state. Although it has been showed that a EM(Engineering Model) with a high discharge coefficient value compared with the TM(Technology Model) fills the overall performance requirements, additional design modifications in some critical parts of the EM were conducted to improve the performance. The configurations of the pressure-control body, the middle flange, and the rips of the inlet body of the EM were modified and the performance tests have been performed with test models. Consequently, the intended improvements have been verified by the performance tests.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.347-348
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• 2007

최근 한반도 및 그 주변에 중소규모 이상의 지진이 빈번히 발생하고 있으나, 국내 대부분의 변전설비들은 내진설계개념을 적용하지 못하고 있는 실정이다. 특히 765kV 변전설비는 산업적, 경제적으로 중요한 국가설비이므로 전력공급 중단을 막기 위해 내진성능확보가 필수적이다. 따라서, 본 연구에서는 765kV 변전소 내 대표설비인 가스절연 개폐장치를 대상으로 내진성능평가를 수행하였으며, 그 결과 지진에 일부 취약한 부위가 발견되어 내진성능개선을 위한 보강이 필요한 것으로 나타났다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.898-899
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• 2007

최근 저압 기중차단기(ACB, Air Circuit Breaker)는 고압 중전기 공인시험제도 및 저압전기기기 안전인증제도와 같은 강제인증대상에서 제외되어 해당 성능에 대한 안전 사각지대에 놓여있다는 지적을 받아왔다. 이에 한국전기연구원에서는 산업자원부 표준화기술개발사업의 일환으로 기중차단기에 대한 표준화 사업을 수행하고 있다. 본 논문에서는 일반 배선용차단기나 누전차단기와는 시험방법 및 설비가 상이한 기중차단기의 동작 및 개폐특성 시험방법을 분석하고 해당 시험을 수행하기 위해 설계하여 구축한 시험설비에 대해 기술하고자 한다. 제안된 성능평가설비들은 기중차단기의 국내 시험은 물론 국제 시험에서도 신뢰성 있게 사용될 것으로 기대한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.230-230
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• 2009

가스절연 개폐장치 (Gas Insulated Switchgear : GIS)의 고체 스페이서에 경사 기능성 재료 (Functionally Graded Material : FGM)가 적용될 때, 절연성능이 크게 향상된다. 본 논문에서는 FGM 스페이서가 적용된 GIS의 전극 및 스페이서의 형상을 변경하여 최대전계를 완화시켰다. 이를 위해 완전요인실험 (Full Factorial Design : FFD)과 결합된 반응표면법 (Response Surface Methodology : RSM)의 최적화기법을 이용하여, 전극 및 스페이서의 최적 형상을 설계하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.831-834
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• 2011

This paper is intended as performance verification of efficient container door Open/Closed detection mechanism for Container Security Device(ConTracer) to container cargo transportation. Container door Open/Closed detection mechanism using Reed sensor is important to satisfies the US Department of homeland security customs and border protections requirements to many types of container door. Also, Verify that the container door is configured correctly and that you can check the illegal opening. In this article, Performance valuation of this Contacer on reed sensor has been verified through field test for each other 30 containers. Once the improvement has been made, we are suggest that propose skills will meet the highest standards for container security safety.

• Aerospace Engineering and Technology
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• v.8 no.2
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• pp.140-148
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• 2009

MOV(Main Oxidizer shut-off Valves) control the combustion of launch vehicle systems by the supply and the isolation of liquid oxygen to a main combustion chamber in launch vehicle systems. Moreover, in the steady operational state, the MOV should secure a constant flow rate of liquid oxygen for combustion instability in the combustion chamber. Concerning the development of MOV, TM(Technology Model) has been manufactured and normal operations of the valve have been verified. However, the Cv of TM has been proved to be too low as compared with a design specification value. Therefore, CFD analysis have been performed by modification of the configurations of TM in order to increase sufficiently Cv of EM(Engineering Model), which is the following model of TM. The modifications of TM configurations such as partial scale-up of valve, increase of stroke length, and outlet angle of 120o would result in a considerable augmentation of Cv. It has been verified by flow capacity tests that the improved Cv of EM is min. 212, which is higher than Cv of TM, 161 by about 32%.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.4
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• pp.28-35
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• 2017

A main oxidizer shutoff valve controls the supply of the oxidizer flow into the combustion chamber of a liquid rocket engine. This shutoff valve also carries out the pre-chilling of oxidizer supply lines by permitting recycling flow for stable transient start of the engine. In the present paper, the flow tests for the recycling line of the valve were conducted in order to evaluate the cooling performance of the main oxidizer shutoff valve. In addition, cryogenic life-cycle tests were performed with an assumption of the increase of spring constant with increasing valve operating times due to ductile-brittle transition effects.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.4
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• pp.393-397
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• 2020

Shunt reactor, a facility for reactive power compensation, is switched several times a day depending on the load pattern. When the circuitbreaker opens the shunt reactor over-voltage is generated by several factors which degrade the insulating performance of internal parts of the circuit-breaker and cause severe voltage stress on the equipment in the power system. Transient phenomenon occurring during the switching of shunt reactor are available in laboratories that verify the performance of the circuit-breaker by simulating the power system. However, it is difficult to measure the transient phenomenon that occurs during actual operation in actual power system due to many limitations. Therefore, this paper deals with the modeling using EMTP to analyze the reignition and current chopping which causes more severe transient recovery voltage in the small inductive current breaking in actual power systems. In addition, this paper analyzes the main phenomenon that cause circuit-breaker failure in opening shunt reactor using EMTP model.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.43-45
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• 2011

경인 아라뱃길에 건설되는 갑문은 기존 운영중인 갑문의 운영특성과 문제점을 파악하여 성능이 개선된 센서, 장비, 자재 등을 적용함으로서 갑문의 안정성과 신뢰성 및 유지관리의 효율성을 향상하였다.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.406-408
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• 2003

본 고에서는 우리나라에 유일한 배전급 실증시험장인 전북 고창 시험장에 배전급 차단기 및 개폐기의 성능을 실증 평가 할 수 있는 기본 시험 시스템 구축에 관한 시험설비에 관하여 소개한다. 본 설비를 구축 활용하므로써 filed에서 발생되는 실증시험을 통해 국내 기자재의 성능 파악 및 신뢰도 향상을 제고하고자 한다.