• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.4
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• pp.250-255
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• 2016

Ocean environmental data such as tide, wind, significant wave height etc. along the expected route were collected and analyzed to secure the safe towing and installation of floating pendulum wave energy converter(FPWEC) at planned sea area. Data from Korea Meteorological Administration(KMA) and Korea Hydrographic and Oceanographic Agency(KHOA) were reviewed and those were used to estimate the external forces exerting on the FPWEC during the towing operation. ANSYS system was used for the structural analysis of the FPWEC which is subject to complex environmental load to confirm the safety.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.140-140
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• 2011

Korea's RPS, which requires that power generation companies obtain a minimum percentage of their generation by using renewable energy, will take effect in 2012. Based on the first-year law enforcement, generation companies have to satisfy 2% of RPS compliance ratio in 2012. Then, the required RPS compliance ratio will increase up to 10% in 2022. Thus generation companies need to construct power plants that utilize various types of renewable energy sources such as PV and wind power. This work is aimed to analyze the cost of such a renewable power source in terms of capital cost, capacity factor, and fuel cost. We provide the analytical expectation on the renewable power generation cost of 2012 focusing on PV, onshore/offshore wind, fuel cell, and IGCC, which are focused by government policy.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.423-426
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• 2007

Pohang Wind Energy Research Center (PoWER-C) is developing a 3 MW Radial Flux Permanent Magnet (RFPM) Synchronous Generator for offshore Wind Energy Converter (WEC). The rotor rpm is 15.7 and the gear ratio is set to be 92.93. The nominal generator rpm at the rated load is about 1459. To reduce the switching loss in the power electronics, the maximum frequency is limited to 100 Hz. This requirement limits the number of pole to six or eight. Permanent magnet excitation is assumed for higher energy yield and higher efficiency. In this report, the requirements and the first efforts for the physics design are described.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.10
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• pp.1354-1359
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• 2014

A survey is carried out for the future energy sources to be used for ship's propulsion and ship's machinery and operations. 44 global experts from Korea, America, Norway, Denmark, Japan and German who are currently working in the shipyard and offshore fields participated at the survey. Quantitative predications on the market shares of various energy sources, such as oil, LNG, fuel cell, wind energy, solar energy and nuclear energy are made. MPI (market prediction index) is considered as a quantitative index for easy comparison between future's energy sources used for ship's propulsion and operations. It is expected that the MPI of LNG becomes twofold in 2020 against 'before 2016'. It could be also said that hydrogen based fuel cell is expected to increase rapidly for the coming years unless a new alternative energy appears.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.47-50
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• 2005

본 연구의 목적은 차세대 대체에너지로 각광받는 풍력발전 중에서 육상발전보다 여러 가지 이점이 있는 해상에서의 한국형 풍력터빈 블레이드의 최적 형상을 위 한 알고리즘을 구현하는 것이다. 풍력터빈 블레이드에서 깃익형의 공기 역학적 특성은 매우 중요한 사항이다. 이를 위해서 익형 성능예측에 층류에서 난류로의 천이과정을 포함하는 XFOIL을 이용하여 블레이드 익형 단면의 양력과 항력 분포를 해석하였다. 첫 번째 수준의 설계변수는 운용범위내의 바람의 속도와 블레이드 지름, 축 회전수이며, 각 단면에서의 비틀림각과 시위길이는 두 번째 수준의 설계 변수이다. 운용범위 내의 각 설계점에서 익형의 공력 변수들과 최소에 너지손실 조건을 이용하여 시위길이와 피치각 분포를 최적화하였다. 각각의 설계점에서 결과를 바탕으로 풍력발전의 설계 운용범위에서 반응면을 구성하고 구배최적화 기법을 통해 요구동력의 제약함수를 만족하고 효율을 최대로 하는 블레이드 형상을 구현하였다. 최적형상에 대해 탈설계점 해석을 수행하여 그 성능을 구하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.213-215
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• 2019

본 논문은 해양공간계획법에 근거한 해양에서의 다양한 용도 경합이 예상되는 울산 부유식 해상풍력발전단지 조성사업에 대하여 살펴보고자 한다. 해양공간계획법에 따르면 다양한 용도가 중첩되는 경우, 자연환경, 사회경제적 여건 및 주변 해역의 이용 및 보전 현황 등을 고려하여 관리의 우선순위를 정해야 한다. 이에, 해상풍력발전단지 설립에 따른 해양환경 및 천연자원 영향성 평가의 경제적 피해액을 추정한다. 이는 해양공간계획 시, 용도지정 우선순위를 정할 때 객관적 자료가 될 수 있고, 나아가 효율적인 풍력발전단지 운영을 위한 기초 자료가 될 것이다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.5
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• pp.82-91
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• 2014

The combined generator system by integrating several renewable energy sources can share the electrical infrastructure and therefore have the advantage of constructing not only the transmission system but also the power conversion system. Among the various combined renewable system, the wind power and wave power has a high possibility of future growth due to the economic feasibility in offshore environment. This kind of large-scale combined systems might be follow the determination by the transmission system operator's directions and control the output profile by focusing at PCC. However, both renewable energies are depend on the unpredictable environmental variation; it is needed to do the compensation devices. In this paper, the ESS compensation plan is proposed to do output determination of the combined generator system by paying attention to active power of utility grid with the analysis of the controllable elements of the wind and wave power generator. The improvement of the new application technique of the combined system is confirmed through using the PSCAD/EMTDC. The entire simulation process was designed by adopting the active power control according to the reference signal of TSO.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.482-483
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• 2009

This paper is foundation paper about national wind map verification using remote sensing, based on analysis of comparison between numerical simulation and remote sensing on complex coastal area of regional coast. As a result analysis using NCAR/NCEP, wind direction of numerical simulation and remote sensing is same. but, wind direction of some case is showed different. Such as this result, if it would be used without verification of analyzed data, present ability of occurring lots of error, and it will be verified based on using survey data or atmospheric data.

• Journal of Wind Energy
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• v.15 no.1
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• pp.91-102
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• 2024

Rapid progress is being made in foundational technology research and engineering for the construction of floating offshore wind farms. There is active development of technology for detachable mooring systems, which have strengths in addressing maintenance issues that arise in floating offshore wind farms and enhance their economic viability. Conventional detachable mooring systems use Kenter links inserted into the middle of mooring chains, which require excessive time for retrieval by Anchor Handling Tug Supply (AHTS) vessels during detachment operations. Moreover, these operations pose risks of link damage and accidents. Therefore, there is a demand for the development of a new concept of detachable mooring systems. The proposed detachable mooring system in this study simultaneously integrates a fairlead chain stoppers (FCS) and submersible mooring pulleys (SMP), which enables all operations to be conducted on the AHTS vessel without underwater tasks. This study detailed the design and safety evaluation of the SMP, a core component of the detachable mooring system, based on the minimum breaking load (MBL) of selected mooring lines according to the capacity of the floating platform. It referenced international codes (AISC Specification for Structural Steel Buildings D5, Pin-Connected Members) for design verification and performed finite element analysis to evaluate the strength of major components in installation and operation scenarios. Additionally, procedures and techniques for evaluating the structural strength of components under uncertain boundary conditions were proposed.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.1
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• pp.31-36
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• 2022

This paper presents the measuring process of dynamic properties of offshore wind power foundation and provides consideration of each step. This Guideline enables to maintain consistent measuring procedure and therefore increase the reliability of test results. Small scaled suction bucket foundation was fabricated to represent the commercial support structure installation mechanism and two cases(free-free, free-fixed) of dynamic tests were performed at workshop. From the tests, the importance of dynamic properties of connection part between suction bucket and tower was figured out. More over, types and configuration of measuring devices are recommended which can help find the natural frequency of wind turbine foundation correctly. In field test, it was found that the natural frequency of suction bucket foundation was increased linearly with the penetration depth due to the confining effect of ambient soil. Meanwhile, it was not easy to get an enough excitation force with normal impact hammer because the N.F of suction bucket model was in the lower range of 0 Hz ~ 5 Hz. Therefore, new excitation method which has enough force and can excite lower frequency range was devised. This study will help develop safety check procedure of suction bucket foundation in field at each installation stage using the N.F measurement.