scholarly journals Evaluation of the Impact of Weather-Related Limitations on the Installation of Offshore Wind Turbine Towers

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3778
Author(s):  
Stephan Oelker ◽  
Aljoscha Sander ◽  
Markus Kreutz ◽  
Abderrahim Ait-Alla ◽  
Michael Freitag
Keyword(s):  
Discrete Event Simulation ◽  
Discrete Event ◽  
Weather Conditions ◽  
Tuned Mass Damper ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Measurement Campaign ◽  
Event Simulation ◽  
Mass Damper ◽  
Wave Heights

Weather conditions have a significant impact on the installation of offshore wind turbines. The rules for installation set clear limits. These limits are usually based on estimations of various experts and not on real assumptions and measurements on-site. When wind speeds and wave heights are too high, work cannot be carried out, and this leads to delays and additional costs. Therefore, we have carried out a measurement campaign during the installation of rotor blades to investigate to which extent the limits can be adjusted by using a tuned mass damper. The results from the measurement campaign—specifically empirically derived significant wave height limits—are used in a discrete event simulation. This study simulates delays resulting from weather conditions. Based on this, the total installation costs are considered. The results of the measurement campaign show that a safe installation with the use of a damper is possible at wave heights of up to 1.6 m. With the discrete event simulation, it is possible to prove that 17.9% can be saved for the costs of the installation vessel. In addition, the wind farm could be erected 32 days faster. Thus, it can be stated that the use of a tuned mass damper simplifies the installation from a technical point of view and is economical.

scholarly journals Application of an Eddy Current-Tuned Mass Damper to Vibration Mitigation of Offshore Wind Turbines

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3319 ◽  
Author(s):  
Jijian Lian ◽  
Yue Zhao ◽  
Chong Lian ◽  
Haijun Wang ◽  
Xiaofeng Dong ◽  
...  
Keyword(s):  
Eddy Current ◽  
Wind Farm ◽  
Permanent Magnets ◽  
Tuned Mass Damper ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Small Scale ◽  
Vibration Mitigation ◽  
Mass Damper ◽  
Extreme Winds

Offshore wind turbine (OWT) structures are highly sensitive to complex ambient excitations, especially extreme winds. To mitigate the vibrations of OWT structures under windstorm or typhoon conditions, a new eddy current with tuned mass damper (EC-TMD) system that combines the advantages of the eddy current damper and the tuned mass damper is proposed to install at the top of them. In the present study, the electromagnetic theory is applied to estimate the damping feature of the eddy current within the EC-TMD system. Then, the effectiveness of the EC-TMD system for vibration mitigation is demonstrated by small-scale tests. Furthermore, the EC-TMD system is used to alleviate structural vibrations of the OWT supported by composite bucket foundations (CBF) under extreme winds at the Xiangshui Wind Farm of China. It is found that the damping of the EC-TMD system can be ideally treated as having linear viscous damping characteristics, which are influenced by the gaps between the permanent magnets and the conductive materials as well as the permanent magnet layouts. Meanwhile, the RMS values of displacements of the OWT structure can be mitigated by 16% to 28%, and the acceleration can also be reduced significantly. Therefore, the excellent vibration-reducing performance of the EC-TMD system is confirmed, which provides meaningful guidance for application in the practical engineering of OWTs.

scholarly journals Improving the Installation of Offshore Wind Farms by the use of Discrete Event Simulation

2015 ◽  
Author(s):  
Yohannes T. Muhabie ◽  
Jean-David Caprace ◽  
Cristian Petcu ◽  
Philippe Rigo
Keyword(s):  
Discrete Event Simulation ◽  
Wind Farm ◽  
Discrete Event ◽  
Probabilistic Approach ◽  
Wind Farms ◽  
Distance Matrix ◽  
Offshore Wind ◽  
Weather Data ◽  
The Real ◽  
Event Simulation

The offshore wind energy development is highly affected by the condition of the weather at sea. Hence, it demands a well-organized planning of the overall process starting from the producers’ sites until the offshore site where the turbines will finally be installed. The planning phase can be supported with the help of Discrete Event Simulation (DES) where weather restrictions, distance matrix, vessel characteristics and assembly scenarios are taken into account. The purpose of this paper is to simulate the overall transport, assembly and installation of the wind turbine components at sea. The analysis is carried out through DES considering both the real historical weather data (wind speed and wave height) and probabilistic approach. Results of the study, applied to the real Offshore Wind Farm (OWF) configuration, are showing a good agreement between the two proposed models. The results point out that the probabilistic\ approach is highly affected by the semi-random numbers used to model the stochastic behavior of the input variable so that several iterations (200 to 400) are required to reach the convergence of the simulation outputs. We suggest that seasonality of the outputs of both models are preserved, i.e. the variation of the results depending on the variation of the weather along the year. These findings provide a new framework to address risks and uncertainties in OWF installations.

scholarly journals Motion Control of Pentapod Offshore Wind Turbines under Earthquakes by Tuned Mass Damper

2019 ◽  
Vol 7 (7) ◽  
pp. 224 ◽  
Author(s):  
Wenhua Wang ◽  
Xin Li ◽  
Zuxing Pan ◽  
Zhixin Zhao
Keyword(s):  
Seismic Waves ◽  
Passive Control ◽  
Control Method ◽  
Tuned Mass Damper ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Integrated Analysis ◽  
Analysis Model ◽  
Mass Damper ◽  
Structural Responses

The dynamic characteristics of a bottom-fixed offshore wind turbine (OWT) under earthquakes are analyzed by developing an integrated analysis model of the OWT. Further, the influence of the interactions between the rotor and support system on the structural responses of the OWT subjected to an earthquake is discussed. Moreover, a passive control method using a tuned mass damper (TMD) is applied to the OWT to control the responses under earthquakes. The effects of the mass ratio, location and tuned frequency of the TMD on controlling structural responses of the OWT under different recorded seismic waves are studied.

scholarly journals Active tuned mass damper for damping of offshore wind turbine vibrations

Wind Energy ◽  
2016 ◽  
Vol 20 (5) ◽  
pp. 783-796 ◽  
Author(s):  
Mark L. Brodersen ◽  
Ann-Sofie Bjørke ◽  
Jan Høgsberg
Keyword(s):  
Wind Turbine ◽  
Tuned Mass Damper ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Mass Damper

scholarly journals An Investigation of Passive and Semi-Active Tuned Mass Dampers for a Tension Leg Platform Floating Offshore Wind Turbine in ULS Conditions

2016 ◽  
Author(s):  
Semyung Park ◽  
Matthew A. Lackner ◽  
John Cross-Whiter ◽  
A. Rodriguez Tsouroukdissian ◽  
William La Cava
Keyword(s):  
Wind Turbine ◽  
Active Control ◽  
Wind Turbines ◽  
Structural Control ◽  
Tuned Mass Damper ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Tension Leg Platform ◽  
Tuned Mass Dampers ◽  
Mass Damper

Floating offshore wind turbines are able to access deeper waters with stronger winds, but also have more complicated dynamic behavior than fixed-bottom offshore turbines, potentially resulting in larger loads. Structural control using tuned mass dampers (TMD) is a promising method for mitigating these loads. Previous research on structural control in wind turbines has typically considered passive devices and operational conditions. In this study, the effects of a passive tuned mass damper and a semi-active tuned mass damper, located at the tower top, are analyzed and simulated for the GE Haliade 150–6MW wind turbine located on the Glosten Pelastar tension-leg platform (TLP). The system is simulated using FASTv8, the wind turbine aero-elastic wind turbine simulator developed by NREL, which includes a TMD module capable of modeling passive and semi-active devices. A pendulum-type TMD developed by ESM GmbH, which can oscillate in the fore-aft and side-side directions, is modelled with non-linear position constraints. Semi-active control is defined using an “on-off” TMD damping based on a “ground-hook” control law. Ultimate limit state (ULS) conditions with a parked rotor are simulated, for two different water depths. The results are analyzed in terms of the load reductions at the tower base, nacelle acceleration reduction, and tendon tensions for the various configurations. The impact of TMD stroke limitations and the sensitivity of the results to water depth are investigated. The results will show that structural control can reduce ULS loads in deep water configurations, but are less effective in shallow water. The dynamics of the system that cause this result will be elucidated. The results will also demonstrate that semi-active control can be an effective strategy to further reduce loads and reduce the TMD stroke.

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