• Journal of the Korean Society of Industry Convergence
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• v.2 no.2
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• pp.173-180
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• 1999

When Automobile runs high velocity, it causes sleepy velocity profile then that generates lift force and drag force. Lift force reduce tire friction force. Drag force increase consumed power. For improve automobile performance, reduction of Lift force and Drag force was seriously considered. It measured experimently using wind tunnel, numerically using numerical analysis. Finite difference method is using difference equation and simplifed mesh. This method require less calculation time and computer power than other method.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.3
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• pp.547-553
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• 2024

Hydrogen is considered a key energy source to achieve carbon neutrality through the global goal of 'Net Zero'. Due to limitations in domestic green hydrogen production, Korean companies are interested in importing green hydrogen produced overseas. Because Australia and the Middle East possess high-quality renewable energy resources, they are attracting attention as suitable regions for producing green hydrogen using renewable energy. The cost of constructing and operating a green ammonia plant varies depending on the region. In this study, an economic feasibility comparison of green ammonia plant construction in Australia and the Middle East is conducted. Through this, it is expected to contribute to the economic analysis and feasibility analysis of the project to import hydrogen in the form of green ammonia into Korea.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.2_1
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• pp.269-276
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• 2024

Many countries across the world are making efforts beyond reducing CO₂ levels and declaring 'net zero,' which aims to cut greenhouse gas emissions to zero by not emitting any carbon or capturing carbon, by 2050. Hydrogen is considered a key energy source to achieve carbon neutrality goals. Korean companies are also interested in building overseas green ammonia production plants and importing hydrogen into Korea in the form of ammonia. Green hydrogen production uses renewable energy sources such as solar and wind power, but the variability of power production poses challenges in plant design. Therefore, optimization of the configuration of a green ammonia production plant using renewable energy is expected to contribute as basic information for securing the economic feasibility of green ammonia production.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.506-510
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• 2004

Our fossil fuels will be exhausted and replaced with renewable energies over tile next few decades. And rapidly increasing consumption of primary makes every country recognize the potential significance of climate change and necessity of greenhouse gas reduction. A critical part of the solution is to ratify the Kyoto Protocol and the UNFCC, and to develop and utilize the wind energy. One of the renewable energies, wind energy is increasing competitive in liberalised energy markets and shows annual growth rate of $20\~30\% in past five years. Thus, the purpose of this paper is to describe the necessity and characteristics of wind energy industries, to compare the international development policies of wind energy industries, and to suggest and discuss the alternative development policies of wind energies in Korea

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.117-118
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• 2013

Recent global warming to the promotion of electric vehicles (EV), plug-in hybrid (PEV), including the next generation of cars and solar power, wind power and other renewable energy, and next-generation power grid (smart grid) are getting attention. In addition, the system utilizes the battery life in the industry and the convenience of a variety of social systems, economics, environmental impact, and the inherent potential to change significantly, and you can not walk into a next-generation industrial strategy and the need increases more and more present, and its early commercialization In order to do this, as well as a key energy source, the battery charger for charging efficiency technologies is essential. In this paper, fast charge multiple battery modules and optional modules that can charge distribution charge will be introduced.

• Journal of Drive and Control
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• v.8 no.1
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• pp.33-39
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• 2011

풍력산업은 발전사업과 풍력터빈 제조산업으로 나뉜다. 세계의 풍력터빈의 설치량은 1996년을 기준으로 해서 매년 평균 28.6%의 성장률을 보여왔다[1]. 2008년 이후 그 성장세가 다소 꺾이기는 했지만, 그린에너지에 대한 세계적인 관심과 욕구, 화석연료 의존에서의 탈피 등의 이유로 계속적인 성장이 예상되고 있다. 특히 재생에너지 분야에서는 가장 시장 경쟁력을 확보할 수 있기 때문에 예측의 실현 가능성이 높다 하겠다. 풍력터빈과 그 부품 산업 역시 유럽이 주도적으로 끌고 나가고 있으며, 아시아와 북미의 시장이 대두됨에 따라서 지역의 풍력산업이 활발하게 발전하고 있다. 국내는 발전사업보다는 제조산업에 1차적인 관심이 있으며, 이를 바탕으로 국산화 모델의 개발 및 상용화에 정부와 민간이 힘을 쏟고 있다. 제품의 개발과 상용화는 시장을 바탕으로 이루어지는데, 불행하게도 국내의 풍력발전 시장은 매우 좁아서 국내 풍력터빈 제조사의 성장에 어려운 점이 있다. 하지만, 국내의 중공업기반과 산업수준을 적극 활용하여 터빈 완제품 및 부품산업의 발전을 위하여 국가와 민간차원에서의 노력이 가중되고 있다.

• Advances in Energy Research
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• v.4 no.2
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• pp.163-176
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• 2016

Rapid depletion of fossil based oil, coal and gas reserves and its greater demand day by day necessitates the search for other alternatives. Severe environmental impacts caused by the fossil fire based power plants and the escalating fuel costs are the major challenges faced by the electricity supply industry. Integration of Distributed Generators (DG) especially, wind and solar systems to the grid has been steadily increasing due to the concern of clean environment. This paper focuses on a new simple and fast load flow algorithm named Backward Forward Sweep Algorithm (BFSA) for finding the voltage profile and power losses with the integration of various sizes of DG at different locations. Genetic Algorithm (GA) based BFSA is adopted in finding the optimal location and sizing of DG to attain an improved voltage profile and considerable reduced power loss. Simulation results show that the proposed algorithm is more efficient in finding the optimal location and sizing of DG in 15-bus radial distribution system (RDS).The authenticity of the placement of optimized DG is assured with other DG placement techniques.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.8
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• pp.661-668
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• 2015

We present a design methodology for horizontal-axis tidal turbine blades based on blade element momentum theory, which has been used for aerodynamic design and power-performance analysis in the wind-energy industry. We design a 2-blade-type 1 MW HATT blade, which consists of a single airfoil (S814), and we present the detailed design parameters in this paper. Tidal turbine blades can experience cavitation problems at the blade-tip region, and this should be seriously considered during the early design stage. We perform computational fluid dynamics (CFD) simulations considering the cavitation model to predict the power performance and to investigate the flow characteristics of the blade. The maximum power coefficient is shown to be about 47 under the condition where TSR = 7, and we observed cavitation on the suction and pressure sides of the blade.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.6
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• pp.265-274
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• 2001

Recently, the operation of power systems has become more difficult because the peak demand load is increasing continuously and the daily load factor is getting worse and worse. Also, the consideration of deregulation and global environment in electric power industry is required. In order to overcome those problems, a study on the planning and operation in power systems of dispersed generating sources such as fuel cell systems, photovoltaic systems and wind power systems, has been performed energetically. This paper presents a method for determining an optimal operation strategy of dispersed co-generating sources, especially fuel cell generation systems, considering thermal supply as well as electric power supply. In other words, the optimal operation of those sources can be determined easily by the principle of equal incremental fuel cost and the thermal merit of those sources can be also evaluated quantitatively through Kuhn-Tucker's optimal conditions. In additions, an priority method using the comparison of total cost at the peak load time interval is presented in order ot select the optimal locations of those sources. The validity of the proposed algorithms is demonstrated using a model system.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.5
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• pp.329-335
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• 2008

Recently, super high-speed motor drives have been available due to the development of power electronics technology And they are used in various fields of industry because of their advantages. This paper describes the control algorithm for a permanent magnet synchronous motor(PMSM) drive at the speed of 118,000r/min using DSP and IGBT inverter. Hall sensors are implemented to measure the rotor position and speed, and a speed observer is used to reduce the performance deterioration caused by the low resolution of hall sensors. To enhance the output power capacity in the high-speed operating region, a flux weakening controller which also can work as an anti-wind up controller is used. Computer simulations and experiments are peformed to validate the proposed method.