• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.305-307
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• 2001

The wind power equipment of Ullung island is composed of a hybride type of wind powers and diesel generators. The wind power generation in Ullung island is, howerever, not smooth due to the small capacity and weekness of existing power systems and line. Therefore, it is the purpose of this study to describe the technical problems and its solution through the investigation of actual conditions.

• Journal of Advanced Marine Engineering and Technology
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• 제36권7호
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• pp.935-941
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• 2012

This paper describes a study of conventional electrical rig and simulated application of Flywheel Energy Storage system on the power system of the offshore plants with dynamic positioning system with the following aims: improve fuel consumption on engines, prevent blackout and mitigate voltage sags due to pulsed load and fault. Fuel consumption has been analyzed for the generators of the typical drilling rigs compared with the power plant with Flywheel Storage Unit which has an important aid in avoiding power interruption during DP (Dynamic Positioning) operation. The FES (Fly wheel Energy storage System) releases energy very quickly and efficiently to ensure continuity of the power supply to essential consumers such as auxiliary machinery and thrusters upon main power failure. It will run until the standby diesel generator can start and supply the electric power to the facilities to keep the vessel in correct position under DP operation. The proposed backup method to utilize the quick and large energy storage Flywheel system can be optimized in any power system design on offshore plant.

• 조명전기설비학회논문지
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• 제27권11호
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• pp.57-68
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• 2013

The market for distributed power generation based on renewable energy is increasing, particularly for standalone mini-grid applications in developing countries with limited energy resources. Stand-alone power systems (SAPS) are of special interest combined with renewable energy design in areas not connected to the electric grid. Traditionally, such systems have been powered by diesel engine generator sets (DEGS), but also hybrid systems with photovoltaic and/or wind energy conversion systems (WECS) are becoming quite common nowadays. Hybrid energy systems can now be used to generate energy consumed in remote areas and stand-alone microgrids. This paper describes the design, simulation and feasibility study of a hybrid energy system for a stand-alone power system. A simulated model is developed to investigate the design and performance of stand-alone hydrogen renewable energy systems. The analysis presented here is based on transient system simulation program (TRNSYS) with realistic ventilation load of a large store. Design of a hybrid energy system is site specific and depends on the resources available and the load demand.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.2147-2155
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• 2022

Nuclear safety-related underground liquid storage tanks, such as those used to store fuel for emergency diesel generators, are critical components for safety of hundreds of existing nuclear power plants (NPP) worldwide. Since most of those NPP will continue to operate for decades, a beyond design base (BDB) seismic screening of safety-related underground tanks in those NPP is beneficial and essential to public safety. The analytical methodology for buried tank subjected to seismic effect, including a BDB seismic evaluation, needs to consider both soil-structure and fluid-structure interaction effects. Comprehensive analysis of such a soil-structure-fluid system is costly and time consuming, often subjected to availability of state-of-art finite element tools. Simple, but practically and reasonably accurate techniques for seismic evaluation of underground liquid storage tanks have not been established. In this study, a mechanics based solution is proposed for the evaluation of a cylindrical underground liquid storage tank using hand calculation methods. For validation, a practical example of two underground diesel fuel tanks in an existing nuclear power plant is presented and application of the proposed method is confirmed by using published results of the computer-aided System for Analysis of Soil Structural Interaction (SASSI). The proposed approach provides an easy to use tool for BDB seismic assessment prior to making decision of applying more costly technique by owner of the nuclear facility.

• 한국화재소방학회논문지
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• 제32권1호
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• pp.57-65
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• 2018

본 연구에서는 다중오동작을 포함하고 있는 화재안전정지분석 교육자료를 개발하기 위하여 가상원전에서의 화재안전정지분석을 결정론적 화재분석코드를 사용하여 수행하였다. 교육용 가상원전은 원자로건물과 보조건물로 이루어졌고, 총 22개의 방화지역으로 구성되었다. 교육용 가상원전의 각 방화지역에는 밸브, 펌프, 비상디젤발전기, 스위치기어, 모터제어반, 로직컨트롤러 등의 기기가 배치되었다. 교육용 가상원전 기기들은 두 개의 케이블로 연결되었으며, 각 케이블은 케이블 트레이를 따라서 방화지역을 지나간다고 가정했다. 방화지역분석을 위해 교육용 가상원전에 대한 기기 및 케이블 정보를 데이터베이스화하였고, 다중오동작 시나리오, 기기로직 및 케이블로직을 가정하여 방화지역분석을 수행하였다. 방화지역 분석결과 문제가 되는 케이블과 케이블 트레이에 대해서 3시간 내화성능으로 케이블을 래핑하는 완화조치를 적용하였다.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1213-1220
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• 2022

The Emergency Diesel Generator (EDG) is a critical and essential part of the Nuclear Power Plant (NPP). Due to past catastrophic disasters, critical systems of NPP like EDG are designed to meet high dependability requirements. Therefore, we propose a framework for the dynamic reliability assessment using the Fault Tree and the Dynamic Bayesian Network. In this framework, the information of the component's failure probability is updated based on observed data. The framework is powerful to perform qualitative as well as quantitative analysis of the system. The validity of the framework is done by applying it on several NPP systems.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.967-973
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• 2021

In 2011, an earthquake and subsequent tsunami hit the Fukushima Daiichi Nuclear Power Plant, causing simultaneous accidents in several reactors. This accident shows us that if there are several reactors on site, the seismic risk to multiple units is important to consider, in addition to that to single units in isolation. When a seismic event occurs, a seismic-failure correlation exists between the nuclear power plant's structures, systems, and components (SSCs) due to their seismic-response and seismic-capacity correlations. Therefore, it is necessary to evaluate the multi-unit seismic risk by considering the SSCs' seismic-failure-correlation effect. In this study, a methodology is proposed to obtain the seismic-response-correlation coefficient between SSCs to calculate the risk to multi-unit facilities. This coefficient is calculated from a probabilistic multi-unit seismic-response analysis. The seismic-response and seismic-failure-correlation coefficients of the emergency diesel generators installed within the units are successfully derived via the proposed method. In addition, the distribution of the seismic-response-correlation coefficient was observed as a function of the distance between SSCs of various dynamic characteristics. It is demonstrated that the proposed methodology can reasonably derive the seismic-response-correlation coefficient between SSCs, which is the input data for multi-unit seismic probabilistic safety assessment.

• 조명전기설비학회논문지
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• 제29권12호
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• pp.55-60
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• 2015

PG and RG methods are widely known method for calculating the capacity of the emergency generator in construction electrical installation. PG and RG methods are mainly used as a saving a life, fire protection, fire fighting in construction. Because no long distance between the emergency generator and electric motor feeder, the relatively small motor power in construction electrical installation, the capacity of generator in PG and RG methods are little problem of voltage and reactive power of generator. However in many cases the application of the PG and RG method is difficult in the Chemical Plant because it is long distance between the generator and the motor Feeder and motor capacity is very large. Motor starting power factor is about 0.2 lagging power factor and motor starting current is about 6times during motor staring. Also Most of the staring current component is a reactive power component. therefore, it is many cases that lack of reactive power and excess of allowable voltage drop limit and After selection of emergency diesel generator, problems happen during motor starting. Therefore, to be selection of effective emergency generator, active generator power, reactive power and the required reactive power during large motor starting should be considered in chemical plant. It is also required of the verification process through simulation because hand calculation is very difficult considering study cases.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.689-690
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• 2015

국내 최초 원전인 고리1호기는 지난 2007년 30년의 운전수명을 마친 뒤 정부의 안전점검을 거쳐 10년간 연장운전에 들어갔다. 이 과정에서 원전의 비상 전원 계통 신뢰성 확보를 위해 설계수명을 초과한 35년 된 노후 비상디젤발전기(Emergency Diesel Generator, 이하 EDG)를 지난 2013년 4월부터 9월까지 약 6개월에 걸쳐 교체하게 되었으며, 국내 원전 EDG 총 42대 중 18대가 20년 넘게 운영되고 있고, 2025년까지 고리 1호기를 후속으로 월성1호기, 고리2호기, 고리3호기, 고리4호기, 한빛1호기 순으로 40년 승인된 운전 인허가 기간이 만료된다.[1]. 본 연구에서, Class 1E EDG 교체 시 신규 EDG 설계기준, 용량결정, 해석 및 평가에 대한 기술적 방법들을 고리1호기의 사례를 통해 고찰하였다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제3권2호
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• pp.141-149
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• 2011

The world is facing a challenge in meeting its needs for energy. Global energy consumption in the last halfcentury has increased very rapidly and is expected to continue to grow over the next 50 years. However, it is expected to see significant differences between the last 50 years and the next. This paper aims at introducing a good solution to replace or work with conventional marine power plants. This includes the use of fuel cell power plant operated with hydrogen produced through water electrolysis or hydrogen produced from natural gas, gasoline, or diesel fuels through steam reforming processes to mitigate air pollution from ships.