• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.4
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• pp.50-58
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• 2016

Korean Space Launch Vehicle (KSLV-II) Propellant Supply System charges liquid oxygen and kerosene to each propellant tank for the stages. To charge the launch vehicle propellant tank safety, the propellant charge flow rates and scenarios should be defined. First, the Propellant Supply System was modeled with 1D flow analysis program. The control valve capacity and orifice size were calculated by performing the 1D steady state simulation. Second, the 1D transient simulation was performed by using the steady state simulation results. As propellants were being charged at the each tank, the increased tank liquid level decreases the charge flow rate. Consequently, the proposed supply system satisfies the required design charging conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.762-767
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• 2017

This paper presents an analysis for improving the power transfer capability in transmission lines caused by the movable load charging of electric vehicles (EVs). EVs are expected to be used more widely and replace gas fuel vehicles in the near future due to the shortage of fossil fuels and for environmental preservation. Movable load charging of EVs could lead to the convergence of transferred power flow and overloading conditions in transmission lines in a specific area of a power system, which is conventionally based on estimated fixed load capability. To analyze these conditions, the New England Test System was divided into four regions based on the load characteristics, and different charging scenarios were considered. In these scenarios, the regional power load was highly increased to 31% based on the standard charging capacity of an EV. As a solution to the overloading problem of transmission lines, a TCSC was installed serially on the overloaded line to directly control the transferred power under limited line capability (100% load capability). The simulation showed that the application of a few TCSCs could efficiently and economically control the line capability problem caused by movable load charging of EVs.

• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.90-90
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• 2003

한국항공우주연구원은 액체추진기관 시스템을 이용한 3단형과학로켓(이하 KSR-III)을 국내 최초로 개발하여 비행시험을 수행하였다. 액체추진기관 로켓의 비행시험을 위해서는 이전의 고체 추진기관을 이용한 과학로켓 1, 2와는 달리 비행시험 조건에 부합하게 액체추진제 및 가압제 등을 공급하는 지상설비가 필요하다. 이에 한국항공우주연구원은 독자적으로 비행시험에 필요한 제반 설비를 갖춘 발사장을 구축하였다. KSR-III는 압축 헬륨가스(GHe)를 이용하여 연료(Jet A-1)와 산화제(LOx)를 가압하여 추력을 얻는 액체추진기관 시스템이다. 따라서 발사장에서의 지상공급설비는 유공압 설비와 발사시나리오에 따라 해당 부품을 제어하고 자료를 저장하는 제어/계측 설비 및 기타설비들로 구성되어 있다. 지상공급설비 중 유공압 설비는 LOx의 저장 및 기체 내 산화제 탱크의 충전을 위한 산화제 공급설비, Jet A-1의 저장 및 기체 내 연료 탱크의 충전을 위한 연료 공급 설비, 지상설비용 밸브구동 및 기체 내부 퍼지 등에 필요한 질소($N_2$)를 저장/공급하는 설비, 기체내부 밸브 구동 및 가압제로 사용되는 기체헬륨(He)을 저장/공급하는 설비들로 구성되어 있다. 이러한 구축된 공급설비는 기능시험, 연계시험 등의 각종 입증시험을 통해 그 성능을 검증한 후 단인증모델(SQTM)을 이용하여 발사 시나리오에 따른 추진제 공급능력을 입증한 후 KSR-III의 비행시험을 성공적으로 수행하였다. 수행된 연구결과는 향후 건설되어질 우주센터내의 발사장 기반설비 설계의 기초 자료로 활용할 수 있을 것이다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.68-70
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• 2021

The wind power generators installed in the Jeju area have already exceeded the supply in the Jeju area and are being thrown away. Accordingly, the government is conducting research on installing a 2MWh-class ESS(energy storage system) through a technology development project to charge wasted power and use it in an electric vehicle charging station. In this paper, in order to stably install a 2MWh class ESS, the electric vehicle charging model and ESS discharge model were modeled and simulated using Matlab Simulink. Through simulation, it was verified that the 2MWh class ESS operates stably in various scenarios.

• Journal of the Korean Institute of Gas
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• v.12 no.4
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• pp.29-33
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• 2008

The focus of this study is to develop a virtual reality program for safe training and virtual reality of hydrogen station. This programme consists of 4 modules such as hydrogen and safety module, hydrogen station module, hypothetical experience module, and accident scenarios module for hydrogen experts. User can experience with principles and operation condition and collect the information of hydrogen station by this programme and can simultaneously study the probable scenarios, emergency response plan/standard operating procedure about hydrogen stations. It makes it possible to educate and safety publicity for the trainee. This virtual reality program will be expected to be helpful for hydrogen station's construction propagation and technology development which is essential for hydrogen energy induction.

• Journal of the Korean Institute of Gas
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• v.22 no.5
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• pp.38-45
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• 2018

Jet fire, pool fire, and vapor cloud explosion are major accident scenarios in LPG filling station. The protection wall would mitigate radiation effect in a jet fire. In case of a pool fire, the protection wall would restrict expanding the pool area. The protection wall might both obstruct the dispersion of released vapor and protect blast overpressure in a vapor cloud explosion scenario. In this paper, An availability assessment method of the protection wall how much reduce damage to receptors is proposed. Additionally application cases are presented for the effectiveness of protection wall in the LPG filling station. The study shows that the protection wall can effectively reduce the death probabilities of receptors located behind the wall in cases of the jet fires and the vapor cloud explosions.

• Journal of the Korean Institute of Gas
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• v.28 no.1
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• pp.85-99
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• 2024

As the proliferation of hydrogen electric vehicles accelerates, there is observed diversification in hydrogen refueling station models. This diversification raises safety concerns for different types of stations. This study conducted a quantitative risk assessment of a multi-vehicle hydrogen station, capable of simultaneously refueling cars, buses, and trucks. Utilizing Gexcon's Effects&Riskcurves Software, scenarios of fire and explosion due to hydrogen leaks were assessed. The study calculated the impact distances from radiative heat and explosion overpressure, and measured risks to nearby buildings and populations. The largest impact distance was from fires and explosions at dispensers and high-pressure storage units. High-pressure storage contributes most significantly to personal and societal risk. The study suggests that conservative safety distances and proper protective measures for these facilities can minimize human and material damage in the event of a hydrogen leak.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.298-299
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• 2011

The impacts of EV charging demands on power system such as increased peak demands may be developed by means of modeling a stochastic distribution of charging and a demand dispatch calculation. Optimization processes are proposed to determine optimal demand distribution portions so that charging costs and demands can be managed optimally. There are two optimization methods which have different effects on the outcome. These focus either on the Electric vehicle customer side (cost optimization) or the System Operator side (Load-weighted optimization).

• Journal of the Economic Geographical Society of Korea
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• v.15 no.1
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• pp.95-115
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• 2012

The initial market of alternative-fuel vehicle (AFV) will show geographically uneven distribution due to AFV's high price, and thus efficient location model should consider spatial variation of demand. This paper estimates AFV trips by incorporating an AFV demand estimation model with origin-destination (OD) trips. The estimates are the input for the flow-refueling location model that maximizes the OD flows that can be refueled by the given number of stations considering AFV's limited range per refueling. A scenario analysis is conducted by varying assumptions in estimating demands and AFV acceptance rate. Optimal location alternatives for Orland metropolitan area are provided and results are compared.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.2
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• pp.279-287
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• 2012

Recharging battery in electric vehicle takes a quite long time compared with gasoline and diesel vehicle which is a problem, the industries should solve, to introduce the electric vehicle into the market. For this reason, the institutions are suggesting a method replacing the discharged battery to recharged battery which is recharged in the switching center. However, this technology is still required to make clear the controversial issues such as threats to security and identification of users. In this paper, we explore the factors that threats to securities in battery exchange system and define the security requirements of the battery exchange system to solve suggested issues. The results of the research are expected to be the reference in the other studies of electric vehicle field of the commercialization of the battery recharging methods and analysis of the securities.