• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.25-28
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• 2014

에너지 자립섬은 외부 전력의 유입이 어려운 상황에서 풍력/태양광 발전과 같은 재생 에너지를 주요 발전원으로 운영하는 섬이다. 에너지 자립섬의 운영을 위해서는 전력 수요와 공급량을 예측하여 발전기, 송배전 시스템, ESS 등의 운영 계획 수립이 필요한데 수요 및 공급의 예측은 기상 상황 및 시간 등의 다양한 요소에 영향을 받으므로 예측이 어렵다. 이러한 특성을 감안하여 효율적인 전력망 운영을 위해 기계 학습을 기반으로 한 스마트 그리드 운영 프레임워크의 활용을 통해 이 문제를 해결하고자 한다. 본 논문에서는 자립섬 운영 계획 수립에 필요한 구성 요소를 파악하고 요소들 간의 연계 관계를 분석하여 운영 시스템의 프레임워크 설계안을 제시한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.6
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• pp.129-134
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• 2021

Recently, the demand for electricity is gradually increasing due to the rapid industrial development and the improvement of living standards. In the case of Korea, which is highly dependent on fossil fuels due to such a surge in electricity demand, reduction and freezing of greenhouse gas emissions due to international environmental regulations will immediately lead to a contraction in industrial activities. Accordingly, there are many difficulties in competition with advanced countries that want to link the environment with the country's industrial production activities, and the development of alternative energy as a countermeasure is of great interest around the world. Among these new power generation methods, small-scale power generation facilities with relatively small capacity include photovoltaic generation, wind power generation, and fuel cell generation. Among them, the fuel cell attracts the most attention in consideration of continuous operation, high power generation efficiency, and long-term durability, which are important factors for practical use. Therefore, in this paper, the fuel cell power generation system was researched and constructed by designing the power conversion circuit necessary to finally obtain the AC power used in our daily life by using the DC power generated from the fuel cell as an input.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.11
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• pp.1407-1413
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• 2011

In this paper, the structural design for composite blade was performed and full scale structural test was conducted to verify the structural design and integrity of composite blade. Firstly, FE analysis was performed using commercial software ABAQUS under conditions of rated wind speed and Case H in IEC 61400-2. Lay-up sequence and ply thickness were designed based on FE results. And to verify the structural design, full scale structural test was conducted according to IEC 61400-2 under identical loading conditions of FE analysis. Finally, the force-deflection and local strain behavior of composite blade were evaluated.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.1
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• pp.37-44
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• 2016

This study is concerned with the numerical investigation of dynamic characteristics of 2.5MW-class wind turbine gearbox in which the misalignment improvement of plenary gear shafts by the flexible pins and the dynamic impact response are analyzed by the finite element method. The tooth contact between gears is modelled using the line element having the equivalent tooth stiffness and the contact ratio to accurately and effectively reflect the load transmission in the internal complex gear system. The equivalent tooth stiffness is calculated by utilizing the tooth deformation analysis and the impulse torque is applied to the input shaft for the dynamics response characteristic analysis. Through the numerical experiments, the equivalent tooth stiffness model was validated and the misalignment improvement of planetary gear shafts was confirmed from the comparison with the cases of fixed shafts at one and both ends.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.491-494
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• 2009

This paper introduces the design concepts and characteristics of WinDS3000$^{TM}$ which is a trade mark of Doosan's 3MW offshore/onshore wind turbine. WinDS3000$^{TM}$ has been designed in consideration of high RAMS (Reliability, Availability, Maintainability and Serviceability) and cost effectiveness for the TC Ia condition in GL guideline. An integrated drive train design with an innovative three-stage gearbox has been introduced to minimize nacelle weight of the wind turbine and to enhance a high reliability for transmission. A permanent magnet generator with full converter system has been introduced to get higher efficiency in part load operation, and grid friendliness use of 50 Hz and 60 Hz grid. A pitch regulated variable speed power control with individual pitch system has been introduced to regulate rotor torque while generator reaction torque can be adjusted almost instantaneously by the associated power electronics. An individual pitch control system has been introduced to reduce fatigue loads of blade and system. The wind turbine has been also equipped with condition monitoring and diagnostic systems in order to meet maintainability requirements. And internal maintenance crane in nacelle has been developed. As a result, the maintenance cost was dramatically reduced and maintenance convenience also enhanced in offshore condition.

• Journal of Ocean Engineering and Technology
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• v.33 no.2
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• pp.116-122
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• 2019

Among the various wave power systems, Salter's duck (rotor) is one of the most effective wave absorbers for extracting wave energy. The rotor shape is designed such that the front part faces the direction of the incident wave, which forces it to bob up and down due to wave-induced water particle motion, whereas the rear part, which is mostly circular in shape, reflects no waves. The asymmetric geometric shape of the duck makes it absorb energy efficiently. In the present study, the rotor was investigated using WAMIT (a program based on the linear potential flow theory in three-dimensional diffraction/radiation analyses) in the frequency domain and verified using OrcaFlex (design and analysis program of marine system) in the time domain. Then, an experimental investigation was conducted to assess the performance of the rotor motion based on the model scale in a two-dimensional (2D) wave tank. Initially, a free decay test (FDT) was carried out to obtain the viscous damping coefficient. The pitch response was extracted from the experimental time series in a periodic regular wave for two different wave heights (1 cm and 3 cm). In addition, the viscous damping coefficient was calculated from the FDT result and fluid forces, obtained from WAMIT, are incorporated into the final response of the rotor. Finally, a comparative study based on experimental and numerical results (WAMIT & OrcaFlex) was performed to confirm the performance reliability of the designed rotor.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.1939-1941
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• 1997

In this paper, we simulated the performance of the Cheaju island and developed the hybrid power system based on a least component size design option. This paper performed simulation of economic relation of battery and diesel generation in hybrid power system component.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.122-124
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• 2006

This paper deals with the dynamic analysis of wind power systems with permanent magnet generator (PMG). The dynamic modeling for wind turbines, PMG and dc-dc convertor are performed. On the basis of dynamic simulation model simulation results are obtained. Finally, test results such as cp vs. TSR and generated voltage are given to confirm the analysis.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.704_705
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• 2009

This paper presents a axial flux permanent magnet synchronous generator(AFPMSG), which is suitable for both vertical-axis and horizontal-axis wind turbine generation system. The design and construction features of the AFPMSG are reviewed. The characteristic analysis is performed such as cogging torque and e.m.f waveform, with the aid of a 3D finite element method. The experimental results confirm the characteristic analysis developed.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.462_463
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• 2009

When introducing the existing distribution system, load and power are mixed for wind power generation to be operated unlike the distribution system. Accordingly, if large scale development facilities such as a wind farm is adopted in concentration, the problems need to be examined and analyzed and security measures need to be taken not to out of voltage range.