Search results for " wind power"
showing 10 items of 55 documents
Effect of Wind Turbulence on Extreme Load Analysis of an Offshore Wind Turbine
2019
Abstract Evaluation of dynamic responses under extreme environmental conditions is important for the structural design of offshore wind turbines. Previously, a modified environmental contour method has been proposed to estimate extreme responses. In the method, the joint distribution of environmental variables near the cut-out wind speed is used to derive the critical environmental conditions for a specified return period, and the turbulence intensity (TI) of wind is assumed to be a deterministic value. To address more realistic wind conditions, this paper considers the turbulence intensity as a stochastic variable and investigates the impact on the modified environmental contour. Aerodynam…
Europe's offshore winds assessed with synthetic aperture radar, ASCAT and WRF
2020
Europe's offshore wind resource mapping is part of the New European Wind Atlas (NEWA) international consortium effort. This study presents the results of analysis of synthetic aperture radar (SAR) ocean wind maps based on Envisat and Sentinel-1 with a brief description of the wind retrieval process and Advanced Scatterometer (ASCAT) ocean wind maps. The wind statistics at 10 and 100 m above mean sea level (a.m.s.l.) height using an extrapolation procedure involving simulated long-term stability over oceans are presented for both SAR and ASCAT. Furthermore, the Weather Research and Forecasting (WRF) offshore wind atlas of NEWA is presented. This has 3 km grid spacing with data …
Europe’s offshore winds assessed from SAR, ASCAT and WRF
2019
Abstract. Europe’s offshore wind resource mapping is part of the New European Wind Atlas (NEWA) international consortium effort. This study presents the results of analysis of Synthetic Aperture Radar (SAR) ocean wind maps based on Envisat and Sentinel-1 with a brief description of the wind retrieval process and Advanced SCATterometer (ASCAT) ocean wind maps. The wind statistics at 10m and 100m height using an extrapolation procedure involving simulated long-term stability over oceans is presented for both SAR and ASCAT. Furthermore, the Weather Research and Forecasting (WRF) offshore wind atlas of NEWA is presented. This has 3 km grid resolution with data every 30 minutes during 30 years f…
EFFECTS OF THE PENETRATION OF WIND POWER IN THE BRAZILIAN ELECTRICITY MARKET
2016
Climate variability has been the main driver for renewables in the Brazilian electricity market. This article analyzes the vulnerabilities of the dependence on hydropower in renewable energy production due to climate variation, as well as wind power penetration in Brazil, given a set of wind industry policies. Despite Brazilian renewable energy increase, the study shows the impact in energy supply in north region, due to the lack of transmission infrastructure. In Brazil, the potential trade-offs between renewables growth, and transmission infrastructure inconsistencies in terms of policy implementation are not yet well analyzed. Simulation results show the potential conflicts between energ…
Extended Environmental Contour Methods for Long-Term Extreme Response Analysis of Offshore Wind Turbines1
2020
Abstract Environmental contour method is an efficient method for predicting the long-term extreme response of offshore structures. The traditional environmental contour is obtained using the joint distribution of mean wind speed, significant wave height, and spectral peak period. To improve the accuracy of traditional environmental contour method, a modified method was proposed considering the non-monotonic aerodynamic behavior of offshore wind turbines. Still, the modified method assumes constant wind turbulence intensity. In this paper, we extend the existing environmental contour methods by considering the wind turbulence intensity as a stochastic variable. The 50-year extreme responses …
Semiactive vibration control of offshore wind turbine towers with tuned liquid column dampers using H<inf>&#x221E;</inf> output feedb…
2010
This short paper addresses the problem of vibration in wind turbine towers. These structures are subject to winds and waves causing undesirable vibrations that affect the structure integrity and system performance. In order to mitigate the vibrations of the tower, a controllable tuned liquid column damper is placed on its top. We propose the use of H ∞ control techniques to formulate a control law. Furthermore, the controller uses output feedback to avoid the dependence on the knowledge of the states of the system. Simulation results illustrate the design procedure proposed in this paper.
Numerical and analytical analysis of a monopile-supported offshore wind turbine under ship impacts
2021
Abstract Offshore wind turbines in the vicinity of ship traffic are exposed to increased risks of ship collisions. To better understand the impact mechanism, this paper evaluates the dynamic responses of a monopile-supported wind turbine under ship impacts, using both numerical and analytical methods. The nonlinear finite element method is applied during the numerical simulations, and the wind load effects, soil conditions, and rigid and deformable ship bows are considered. The analytical approach, originally developed based on the energy method, is extended here to address the damping effects of monopile-supported wind turbines. In the case study, the impacts are studied between a 4600-ton…
Offshore wind metadata management
2014
Offshore wind energy is gaining more and more attention from industry and research community due to its high potential in producing green energy and lowering price on electricity consumption. However, offshore wind is facing many challenges, and hence it is still expensive to install in large scale. It therefore needs to be considered from different aspects of technologies in order to overcome these challenges. One of the problems of the offshore wind is that information comes from different sources with diversity in types and format. Besides, there are existing wind databases that should be utilised in order to enrich the knowledge base of the wind domain. This paper describes an approach …
A comparative study on the dynamic response of three semisubmersible floating offshore wind turbines
2019
Abstract Currently, there is a great interest to globally develop offshore wind energy due to the greenhouse effect and energy crisis. Great efforts have been devoted to develop reliable floating offshore wind energy technology to exploit the wind energy resources in deep seas. This paper presents a comparative study of the dynamic response of three different semisubmersible floating wind turbine structures. All the three platforms support the same 5MW wind turbine. The platforms examined are: a V-shaped Semi, an OC4-DeepCwind Semi and a Braceless Semi at 200 m water depth. A dynamic analysis is carried out in order to calculate and compare the performance of these platforms. The comparison…
Active heave compensation of floating wind turbine installation using a catamaran construction vessel
2021
Abstract The application of floating wind turbines is limited by the high cost that increases with the water depth. Offshore installation and maintenance continue to consume a high percentage of the project budget. To improve the installation efficiency of the floating offshore wind turbine, a novel concept is proposed by the SFI MOVE project. Several wind turbine superstructure components are preassembled onshore and carried to the installation site by a catamaran construction vessel. Each assembly can then be installed using only one lift, and the concept is less sensitive to weather conditions. In this paper, a control algorithm of the proposed hydraulic active heave compensator system i…