• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.377-377
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• 2009

Currently, new and renewable energy come into the spotlight, such as solar energy, wind power, fuel cell, hybrid car etc., due to the energy resources is being depleted. In order to solve like this problem, we addressed the roll to roll printing machine for the thin film solar cell by using printing technology. For the this research, we archived concept design and verified propriety.

• 융합신호처리학회논문지
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• 제25권2호
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• pp.94-99
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• 2024

최근 들어 풍력 발전은 신재생 에너지 중에서 높은 효율을 가진 에너지원으로 주목받고 있으며, 이에 따라 전 세계적으로 다양한 기술 개발이 진행되고 있다. 일반적으로 풍력 발전은 풍력 자원이 풍부한 지역에 많은 풍력터빈을 설치하여 운영하는 대형 풍력 농장(Big Wind Farm) 형태로 운영되고 있으나 개발 도상국이나 전력망에서 고립된 지역에서는 오프-그리드(Off-Grid) 형태의 소형 풍력 발전 시스템이 효율적인 솔루션으로 부상하고 있다. 오프-그리드(Off-Grid) 형태의 소규모 발전 시스템을 효율적으로 운영하고 확산시키기 위해서는 실시간 모니터링 시스템의 개발이 요구된다. 소규모 풍력 발전 시스템 구성을 위해 과다한 풍속으로 인한 손상 방지 체계 및 다양한 환경적 요소에 능동적으로 대처하기 위한 실시간 발전소 운영 모니터링 체계 그리고 생산된 전력을 안정적으로 소규모 지역이나 시설에 공급하기 위한 ESS(Energy Storage System) 시스템에 대해 연구하였다. 구현된 시스템은 터빈의 RPM, 발전량, 브레이크 동작, 발전량 등을 모니터링하여 최적 운영환경이 조성되도록 하였다. 구현된 소형 풍력발전 체계는 격오지 도로 조명, 해양 레저 시설, 모바일 통신 기지국 등에 활용될 수 잇으며 RE100 산업 생태계 발전에 기여할 수 있을 것이다.

• International Journal of Advanced Culture Technology
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• 제3권1호
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• pp.101-112
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• 2015

Renewable energy resources play an important part in the world's future. Renewable energy sources have the following components: biomass, geothermal, solar thermal, directs solar, wind, tidal and hydropower. Hydropower is still the most efficient way to generate electricity worldwide. Hydropower projects can contribute as a cheap energy source, as well to encourage the development of small industries across a wide range of new technology; furthermore hydropower systems use the energy in flowing and falling water to produce electricity or mechanical energy. Hydropower systems are classified as large, medium, small, mini and micro according to their installed power generation capacity, as do the following components: water turbines, control mechanisms and electrical transmissions. In this article a review of small hydropower systems has been done on the principles surrounding the fundamentals of hydraulic engineering, the fundamentals of hydrology, identification of sites and economic analysis.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권2호
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• pp.664-677
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• 2014

Wind energy has proven its viability by the emergence of countless wind turbines around the world which greatly contribute to the increased electrical generating capacity of wind farm operators. These infrastructures are usually deployed in not easily accessible areas; therefore, maintenance routines should be based on a well-guided decision so as to minimize cost. To aid operators prior to the maintenance process, a condition monitoring system should be able to accurately reflect the actual state of the wind turbine and its major components in order to execute specific preventive measures using as little resources as possible. In this paper, we propose a fault detection approach which combines cluster analysis and frequent pattern mining to accurately reflect the deteriorating condition of a wind turbine and to indicate the components that need attention. Using SCADA data, we extracted operational status patterns and developed a rule repository for monitoring wind turbine systems. Results show that the proposed scheme is able to detect the deteriorating condition of a wind turbine as well as to explicitly identify faulty components.

• 전기학회논문지
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• 제64권8호
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• pp.1168-1179
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• 2015

This paper presents voltage and frequency control methods for a stand-alone Gasa Island Microgrid in South Korea that can be fully energized by renewable energy resources such as photovoltaic systems and wind turbines. To mitigate the variations of the output of renewable energy resources and supply more reliable electricity to customers, battery energy storage systems (BESSs) are employed in the stand-alone microgrid. The coordination between BESSs and pre-existing diesel generators is an important issue to manage the microgrid more securely. This paper presents voltage and frequency control schemes considering the coordination of BESSs and DGs. The effectiveness for the operating method is validated via simulation studies.

• 한국태양광발전학회지
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• 제6권1호
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• pp.56-68
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• 2020

Cameroon is a lower middle-income country with a population of 25.87 million inhabitants distributed over a surface area of 475,442 ㎢. Cameroon has very rich potentials in renewable energy resources such as solar energy, wind energy, small hydropower, geothermal energy and biomass. However, renewable energy constitutes less than 0.1% of energy mix of the country. The energy generation mix of Cameroon is dominated by large hydropower and thermal power. Cameroon ratified the Paris Agreement in July 2016 with an ambitious 20% greenhouse gas (GHG) emission reduction. This study attempts to investigate some renewable energy deployment policy-instruments that could enable the country enhance renewable energy deployment, gain energy independence, fulfill Nationally Determined Contribution (NDC) and achieve Sustainable Development Goals. It begins with an analysis of the status of energy sector in Cameroon. It further highlights the importance of renewable energy in mitigating climate change by decarbonizing the energy mix of the country to fulfill NDC and SDGs. Moreover, this study proposes some renewable energy deployment policy-solutions to the government. Solar energy is the most feasible renewable energy source in Cameroon. Feed-in Tariffs (FiT), is the best renewable energy support policy for Cameroon. Finally, this study concludes with some recommendations such as the necessity of building an Energy Storage System as well a renewable energy information and statistics infrastructure.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.59.2-59.2
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• 2011

Although there are many activities on the construction of wind farm to produce amount of power from the wind, in practice power productions are not as much as its expected capabilities. This is because a lack of both the prediction of wind resources and the aerodynamic analysis on turbines with far wake effects. In far wake region, there are velocity deficits and increases of the turbulence intensity which lead to the power losses of the next turbine and the increases of dynamic loadings which could reduce system's life. The analysis on power losses and the increases of fatigue loadings in the wind farm is needed to prevent these unwanted consequences. Therefore, in this study velocity deficits have been predicted and aerodynamic analysis on turbines in the far wake is carried out from these velocity profiles. Ainslie's eddy viscosity wake model is adopted to determine a wake velocity and aerodynamic analysis on wind turbines is predicted by the numerical methods such as blade element momentum theory(BEMT) and vortex lattice method(VLM). The results show that velocity recovery is more rapid in the wake region with higher turbulence intensity. Since the velocity deficit is larger when the turbine has higher thrust coefficient, there is a huge aerodynamic power loss at the downstream turbine.

• 수산해양교육연구
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• 제25권1호
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• pp.167-180
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• 2013

A capstone design is regarded as one of cap courses in undergraduate engineering education because it requires most prerequisites and makes students experience real engineering design processes. There have been case studies to show how this subject should be organized, practiced, and optimized. This study shows one of the case studies by focusing offshore wind power, one of newly recognized renewable energy resources, especially targeting for the design of wind turbine foundation and submarine power cable protectors mainly because of current energy and global warming crisis. To pinpoint engineering design, the students'activities during the project and design procedures are monitored, evaluated, and recommended; hence, core factors are addressed to develop successful aim, theory, practice, and other necessities. These factors include creative problem solving abilities; recognition of engineering curriculum; selection of project theme based on significance, ripple effect, and education purpose; team organization by the full brain model; systematization of project process; realization of engineering design; and synthesis of evaluation. In the end, the aftermath and future works are discussed.

• 풍력에너지저널
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• 제14권1호
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• pp.29-36
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• 2023

The analysis of the floating offshore wind turbine platform is based on the procedures provided by the IEC including the International Classification Society, which recommends the analysis in the time domain. But time-domain simulation requires a lot of time and resources to solve tens of thousands of DLCs. This acts as a barrier in terms of floating structure development. For final verification, it requires very precise analysis in the time domain, but from an initial design point of view, a simplified verification procedure to predict the quantity of materials quickly and achieve relatively accurate results is crucial. In this study, a structural design procedure using a design wave applied in the oil and gas industries is presented combined with a conservative turbine load. With this method, a quick design spiral can be rotated, and it is possible to review FOWTs of various shapes and sizes. Consequently, a KRISO Semi-Submersible FOWT platform was developed using a simplified design procedure in frequency-domain analysis.

• Advances in Energy Research
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• 제6권2호
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• pp.103-129
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• 2019

While global demand for energy increases annually, at the same time the demand for carbon-free, sulphur-free and NO_x-free energy sources grows considerably. This state poses a challenge in the research for newer sources like biomass and shale gas as well as renewable energy resources such as solar, wind, geothermal and hydraulic energy. Although wave energy also is a form of renewable energy it has not fully been exploited technically and economically so far. This study tries to explain those reasons in which it is beyond doubt that the demand for wave energy will soon increase as fossil energy resources are depleted and environmental concerns gain more importance. The electrical energy supplied to the grid shall be produced from wave energy whose conversion devices can basically work according to three different systems. i. Systems that exploit the motions or shape deformations of their mechanisms involved, being driven by the energy of passing waves. ii. Systems that exploit the weight of the seawater stored in a reservoir or the changes of water pressure by the oscillations of wave height, iii. Systems that convert the wave motions into air flow. One of the aims of this study is to present the classification deficits of the wave energy converters (WECs) of the "wave developers" prepared by the European Marine Energy Center, which were to be reclassified. Furthermore, a new classification of all WECs listed by the European Marine Energy Center was arranged independently. The other aim of the study is to assess the technological state of the art of these WECs designed and/or produced, to obtain an overview on them.