Wind Tunnel 2-DoF Hybrid/HIL Tests on the OC5 Floating Offshore Wind Turbine

2017 ◽  
Author(s):  
Ilmas Bayati ◽  
Marco Belloli ◽  
Alan Facchinetti
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Real Time ◽  
Offshore Wind ◽  
Test Facility ◽  
Offshore Wind Turbine ◽  
Special Focus ◽  
Floating Offshore Wind Turbine ◽  
Wind Tunnel Tests ◽  
Experimental Implementation

This paper presents the numerical and experimental implementation of a 2 degrees-of-freedom (DoF) setup for simulating the surge and pitch motion of OC5 semi submersible floating offshore wind turbine, through the “hardware-in-the-loop” (HIL) approach during wind tunnel tests. This approach is hybrid since a real-time combination of computations and measurements are carried out during the experiments. This allows to separate the model tests of floating wind turbines into wave/ocean basin and wind tunnel tests, as it is currently done within the H2020/LIFES50+ project respectively at Marintek (Norway) and Politecnico di Milano (Italy), with the possibility of exploiting the advantages of each facility and overcoming the scaling issues and conflicts (e.g. Froude-Reynolds) that are emphasized when it comes to testing both wind and wave in a single test facility. In this paper the modelling approach and experimental implementation are presented, with a special focus on signals and data handling in the real-time HIL control system aimed at minimizing the effect of model/full scale discrepancies. Results are shown for free decays, regular and irregular sea states, showing promising results for the next 6-DoF system being finalized.

Wind tunnel and numerical study of a floating offshore wind turbine based on the cyclic pitch control

2021 ◽  
Vol 172 ◽  
pp. 453-464
Author(s):  
Le Quang Sang ◽  
Qing’an Li ◽  
Chang Cai ◽  
Takao Maeda ◽  
Yasunari Kamada ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Numerical Study ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Floating Offshore Wind Turbine ◽  
Pitch Control

Snap Loads on Mooring Lines of a Floating Offshore Wind Turbine Structure

2014 ◽  
Author(s):  
Wei-ting Hsu ◽  
Krish P. Thiagarajan ◽  
Matthew Hall ◽  
Michael MacNicoll ◽  
Richard Akers
Keyword(s):  
Wind Turbine ◽  
Impact Load ◽  
Offshore Wind ◽  
Mooring Line ◽  
Offshore Wind Turbine ◽  
Special Focus ◽  
Mooring Lines ◽  
Floating Offshore Wind Turbine ◽  
Marine Applications

There are a number of design challenges facing mooring systems of floating offshore wind turbine (FOWT) platforms in an offshore environment. Some unique aspects of the FOWT industry should be considered when examining applicability of established offshore mooring practices. Important among these are: economy and cost effectiveness; light weight minimal platforms; and water depths ranging from 50–300 m. A lighter displacement platform in shallow water, supported by lines with light to moderate pre-tension can result in a higher probability of slack line events and hence snap loads during re-engagement. Such loads can result in shock on the line material and considerably reduce the fatigue life. Such events have the potential to occur in various sea states, and not necessarily limited to extreme conditions. These conditions will be dependent on structure resonant motions, which are influenced by wind loads and moments, wave conditions and mooring line properties. Model tests of typical concepts for FOWT reported in literature have shown occasional slack line episodes. This paper is a review of literature on snap load occurrence in marine applications, including lifting and lowering operations, ROV and diving bell operations. This paper presents a case study of a FOWT. Special focus is on mooring systems which are affected by impact load conditions. Criteria are reviewed and consequences are documented.

scholarly journals Resonance Avoidance Control Algorithm for Semi-Submersible Floating Offshore Wind Turbine

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4138
Author(s):  
Kwansu Kim ◽  
Hyunjong Kim ◽  
Hyungyu Kim ◽  
Jaehoon Son ◽  
Jungtae Kim ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Control Algorithm ◽  
Torque Control ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Resonance Problem ◽  
Exclusion Zone ◽  
Mean Power ◽  
Floating Offshore Wind Turbine ◽  
Avoidance Control

In this study, a resonance avoidance control algorithm was designed to address the tower resonance problem of a semi-submersible floating offshore wind turbine (FOWT) and the dynamic performance of the wind turbine, floater platform, and mooring lines at two exclusion zone ranges were evaluated. The simulations were performed using Bladed, a commercial software for wind turbine analysis. The length of simulation for the analysis of the dynamic response of the six degrees of freedom (DoF) motion of the floater platform under a specific load case was 3600 s. The simulation results are presented in terms of the time domain, frequency domain, and using statistical analysis. As a result of applying the resonance avoidance control algorithm, when the exclusion zone range was ±0.5 rpm from the resonance rpm, the overall performance of the wind turbine was negatively affected, and when the range was sufficiently wide at ±1 rpm, the mean power was reduced by 0.04%, and the damage equivalent load of the tower base side–side bending moment was reduced by 14.02%. The tower resonance problem of the FOWT caused by practical limitations in design and cost issues can be resolved by changing the torque control algorithm.

Sign in / Sign up

Export Citation Format

Share Document