• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.56.2-56.2
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• 2011

As rotor blade of a wind turbine becomes larger to satisfy the economic efficiency for offshore wind farm, the numerical analysis considering wind profile is getting emphasized. In this paper, the study for the power characteristic of a wind turbine is carried out using NREL phase VI wind turbine applied wind profile. The experimental data of NASA Ames wind tunnel for inflow velocity 7m/s is used and the numerical result is obtained by using CFD commercial solver(FLUENT).

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.366-369
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• 2007

This paper presents the general results of the conceptual design of a 3MW class offshore wind turbine named WinDS 3000 under development. In WinDS 3000, an integrated drive train design, three stage gearbox and permanent magnet generator (PMG) with fully rated converters have been introduced. A pitch regulated variable speed power control with individual pitch control has been adopted to regulate rotor torque while generator reaction torque can be adjusted almost instantaneously by the associated power electronics. Through the introduction of WinDS 3000, it is expected that helpful to understanding of the development status of 3MW offshore wind turbine.

• 전력전자학회논문지
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• 제21권3호
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• pp.238-248
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• 2016

In this study, an automatic command mode transition strategy of direct power control (DPC) is proposed for permanent magnet synchronous generators (PMSGs) medium-voltage (MV) offshore wind turbines (WTs). Benchmarking against the control methods are performed based on a three-level neutral-point-clamped (NPC) back-to-back type voltage source converter (VSC). The ramping rate criterion of complex power is utilized to select the switching vector in DPC for a three-level NPC converter. With a grid command and an MPPT mode transition strategy, the proposed control method automatically controls the generated output power to satisfy a grid requirement from the hierarchical wind farm controller. The automatic command mode transition strategy of DPC is confirmed through PLECS simulations based on Matlab. The simulation result of the automatic mode transition strategy shows that the proposed control method of VOC and DPC achieves a much shorter transient time of generated output power than the conventional control methods of MPPT and VOC under a step response. The proposed control method helps provide a good dynamic performance for PMSGs MV offshore WTs, thereby generating high quality output power.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.237-238
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• 2015

This paper analyzed the impact of Voltage Sourced Converter High Voltage Direct Current(VSC HVDC) connected an offshore wind power on the Jeju Island electrical power system. Wind power output fluctuates with the changing of wind speed. By changing wind power output occupancy into 100%, 60%, 10% respectively, we can understand the bus voltage distribution controlled by VSC HVDC. PSS/E is used to analyze steady-state simulation results which show effectiveness of the VSC HVDC for Jeju Island power system.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.240-242
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• 2011

Wind power system is generally divided into the onshore wind turbine and the offshore wind turbine according to site locations. The offshore wind turbine is manufactured as a closed nacelle cooling system including a heat exchanger to prevent corrosion, but the onshore wind turbine is manufactured as open nacelle cooling system dependent on only the outdoor air without a heat exchanger. The indoor of a nacelle which is composed of a generator, foil power converters and a gearbox with a lot of heat is very narrow and airtight. This aim of the study is to demonstrate the temperature effect depending on positions of air-supply and exhaust ports. And this study discusses the flow field and removal efficiency of heat caused by components.

• 한국전기전자재료학회논문지
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• 제37권3호
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• pp.286-291
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• 2024

Research on aged insulation of cables by stress is constantly being considered for reliable and stable power transmission of offshore wind farms. This study aimed to evaluate the insulation characteristic of aged XLPE (cross-linked polyethylene) insulation for application of offshore wind farms. In this study, The XLPE insulation of cable was set as various mechanical strains. The XLPE insulation is exposed to the mechanical stress below yield strain of 5%, 10%, and 20%. Aged samples were tested by using the method of AC BDV (alternative current breakdown voltage), tensile strength, elongation, and SEM (scanning electron microscope) to obtain insulation characteristics. The experimental results show that the dielectric breakdown of the sample with a strain 20% was 50% lower than the unaged sample; thereby, demonstrating that the mechanical strain that occurred in the submarine cables can weaken the insulation characteristics. Therefore, mechanical strain should be monitored when laying and operating submarine cables for offshore wind farms.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.244-245
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• 2013

This paper proposes a control algorithm for permanent magnet synchronous generator with a back-to-back three-level neutral-point clamped voltage source converter in a medium-voltage offshore wind power system under unbalanced grid conditions. The proposed control algorithm particularly compensates for the unbalanced grid voltage at the point of common coupling in a collector bus of offshore wind power system. This control algorithm has been formulated based on the symmetrical components in positive and negative rotating synchronous reference frames under generalized unbalanced operating conditions. Instantaneous active and reactive power are described in terms of symmetrical components of measured grid input voltages and currents. Negative sequential component of ac input current is injected to the point of common coupling in the proposed control strategy. The amplitude of negative sequential component is calculated to minimize the negative sequential component of grid voltage under the limitation of current capability in a voltage source converter. The proposed control algorithm makes it possible to provide a balanced voltage at the point of common coupling resulting in the generated power of high quality from offshore wind power system under unbalanced network conditions.

• 신재생에너지
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• 제19권2호
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• pp.40-58
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• 2023

Several offshore wind power conflicts occur due to the problems in which the site selection process led by private operators is improperly managed. To review the institutional improvement measures that solve this problem, domestic and foreign institutions and operational cases were comparatively analyzed, focusing on key actors from the multi-level governance perspective. First, the status of the site selection process in the Republic of Korea, major issues in stakeholder conflicts, and discussions on the planned site system-related laws (draft) were reviewed. Next, the site selection process and relevant cases in Germany, the Netherlands, and Japan were analyzed. In all these countries, site selection is done by the central government. In Germany and the Netherlands, maritime-related ministries establish overall offshore wind power site plans and conduct strategic environmental assessments for these plans. Futhermore, in the process of determining each individual site, extensive site investigation including environmental assessments are conducted. This aspect needs to be supplemented in the discussion on the direction of institutional improvement in the Republic of Korea.

• Journal of Advanced Marine Engineering and Technology
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• 제38권9호
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• pp.1075-1080
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• 2014

본 연구는 5MW급 해상풍력 하부구조물개발에 있어 설계에 필요한 다양한 해양환경 조건에 대하여 높은 안정성 확보가 요구되는 해상용 풍력발전 하부구조물과 관련, 구조물의 설계방법을 제시하고 그 안정성을 고찰하여 관련 기술 분야에 기여함을 목표로 한다. 특히, 5MW급 해상풍력발전 시스템에 대해 시험영역에서 큰 바람의 방향이 지속되고 있는 동안에 동시에 발달된 파도의 계산에 대한 정보를 제공한다. 그러므로 바람의 영역과 접근하는 파동 행열간의 관련성을 검토하여 강도, 방향 그리고 시간의 이동성을 계산할 수 있음을 확인하였다. 쇄파에서의 국부적인 압력분포를 물리적인 모델링과 수치적 모델링을 통해 조사하는 것이 가능하다. 해상 풍력 에너지 변환장치의 지지구조물들에 대해 최근 적용된 구조 및 피로에 대한 평가는 일반 설계규칙에 근거했다. 5MW 해상풍력 하부구조물은 제약조건이 많아 단일구조로 취급하는데 이는 생산에서 높은 안전계수를 고려해야함을 의미한다.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제1권3호
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• pp.161-170
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• 2012

전 세계적으로 신재생에너지에 대한 관심이 고조되고 있다. 특히 풍력은 높은 경제성으로 인하여 연구개발이 활발히 진행되고 있다. 국내에 서도 서남해 지역에 대규모 해상 풍력발전단지 연구개발을 진행중에 있다. 현재 풍력발전단지 운영을 위한 SCADA 시스템의 국내 기술 수준은 매우 낮은 수준으로 대규모 발전단지에 적용이 가능한 SCADA 시스템 개발이 시급한 실정이다. 따라서 본 논문에서는 대규모 해상풍력발전단지 SCADA 시스템 개발을 위해서 필요한 고려 사항과 이를 바탕으로 SCADA 시스템 설계 내용을 기술하였다.