Dynamic Response of a Semi-Submersible Floating Offshore Wind Turbine in Storm Condition

2012 ◽  
Vol 260-261 ◽  
pp. 273-278 ◽  
Author(s):  
Hai Tao Wu ◽  
Jin Jiang ◽  
Jing Zhao ◽  
Xiao Rong Ye

The paper focuses on a semi-submersible floating offshore wind turbine (FOWT) and analyses its dynamic response in storm condition. The wind load is calculated based on wind block model; the hydrodynamic load is modeled using Potential Theory and Morison Equation. The time-domain dynamic response of the FOWT is simulated by SESAM software with duration of 3 hours. The performance of the FOWT is analyzed based on time history responses and response spectrums. The results show some unique characteristics that differ from offshore platforms and the analysis proofs that the performance is acceptable and the design is reliable.

Author(s):  
Yan Li ◽  
Xiaoqi Qu ◽  
Liqin Liu ◽  
Peng Xie ◽  
Tianchang Yin ◽  
...  

Abstract Simulations are conducted in time domain to investigate the dynamic response of a spar-type floating offshore wind turbine (FOWT) under the freak wave scenarios. Toward this end, a coupled aero-hydro-mooring in-house numerical code is adopted to perform the simulations. The methodology includes a blade-element-momentum (BEM) model for simulating the aerodynamic loads, a nonlinear model for simulating the hydrodynamic loads, a nonlinear restoring model of Spar buoy, and a nonlinear algorithm for simulating the mooring cables. The OC3 Hywind spar-type FOWT is adopted as an example to study the dynamic response under the freak wave conditions, meanwhile the time series of freak waves are generated using the random frequency components selection phase modulation method. The motion of platform, the tension applied on the mooring lines, and the power generation performance are documented in several cases. According to the simulations, it is indicated that when a freak wave acts on the FOWT, the transient motion of the FOWT is induced in all degrees-of-freedom, as well as the produced power decreases rapidly. Furthermore, the impact of freak wave parameters on the motion of FOWT is discussed.


Author(s):  
Koji Tanaka ◽  
Iku Sato ◽  
Tomoaki Utsunomiya ◽  
Hiromu Kakuya

Abstract In this paper, we describe the analysis of the dynamic response of a 2 MW floating offshore wind turbine (FOWT) at the time of typhoon attack in the actual sea area. In order to introduce floating offshore wind turbine in Asia, it is essential to evaluate the influence of typhoon attack accurately. This FOWT, named HAENKAZE is the only FOWT to operate commercially in areas where typhoons occur. On July 3rd, 2018, the strongest typhoon (Prapiroon) at the installed area of the FOWT since its installation approached the HAENKAZE. The central atmospheric pressure of the typhoon at the closest time was 965 hPa, the maximum instantaneous wind speed at the hub height was 52.2 m/s, and the maximum wave height was 7.1 m. In this paper, the dynamic response of the floating body at the time of typhoon attack is compared for the measured and the simulated values. As a result of the comparison, basically a good agreement has been obtained between the measured and the simulated values except for yaw response, for which the simulated values considerably overestimate the measured values.


Author(s):  
Yougang Tang ◽  
Yan Li ◽  
Peng Xie ◽  
Xiaoqi Qu ◽  
Bin Wang

Abstract Simulations are conducted in time domain to investigate the dynamic response of a SPAR-type floating offshore wind turbine under the scenarios with freak wave. Towards this end, a coupled aero-hydro numerical model is developed. The methodology includes a blade-element-momentum model for aerodynamics, a nonlinear model for hydrodynamics, a nonlinear restoring model of SPAR buoy, and a nonlinear algorithm for mooring cables. The OC3 Hywind SPAR-type FOWT is chosen as an example to study the dynamic response under the freak conditions, while the time series of freak wave is generated by the Random Frequency Components Selection Phase Modulation Method. The motions of platform, the tensions in the mooring lines and the power generation performance are documented in different cases. According to the simulations, it shows that the power coefficient of wind turbine decreased rapidly at the moment when freak wave acted on the floating structure.


2019 ◽  
Vol 7 (4) ◽  
pp. 115 ◽  
Author(s):  
Yane Li ◽  
Conghuan Le ◽  
Hongyan Ding ◽  
Puyang Zhang ◽  
Jian Zhang

The paper discusses the effects of mooring configurations on the dynamic response of a submerged floating offshore wind turbine (SFOWT) for intermediate water depths. A coupled dynamic model of a wind turbine-tower-floating platform-mooring system is established, and the dynamic response of the platform, tensions in mooring lines, and bending moment at the tower base and blade root under four different mooring configurations are checked. A well-stabilized configuration (i.e., four vertical lines and 12 diagonal lines with an inclination angle of 30°) is selected to study the coupled dynamic responses of SFOWT with broken mooring lines, and in order to keep the safety of SFOWT under extreme sea-states, the pretension of the vertical mooring line has to increase from 1800–2780 kN. Results show that the optimized mooring system can provide larger restoring force, and the SFOWT has a smaller movement response under extreme sea-states; when the mooring lines in the upwind wave direction are broken, an increased motion response of the platform will be caused. However, there is no slack in the remaining mooring lines, and the SFOWT still has enough stability.


Author(s):  
Tonio Sant ◽  
Daniel Buhagiar ◽  
Robert N. Farrugia

Nowadays there is increased interest to incorporate energy storage technologies with wind turbines to mitigate grid-related challenges resulting from the intermittent supply from large-scale offshore wind farms. This paper presents a new concept to integrate compressed air energy storage (CAES) in floating offshore wind turbine (FOWT) structures. The FOWT support structures will serve a dual purpose: to provide the necessary buoyancy to maintain the entire wind turbine afloat and stable under different met-ocean conditions and to act as a pressure vessel for compressed air energy storage on site. The proposed concept involves a hydro-pneumatic accumulator installed on the seabed to store pressurized deep sea water that is pneumatically connected to the floating support structure by means of an umbilical conduit. The present study investigates the technical feasibility of this concept when integrated in tension leg platforms (TLPs). The focus is on the impact of the additional floating platform weight resulting from the CAES on the dynamic response characteristics and loads when exposed to irregular waves. A simplified model for sizing the TLP hull for different energy storage capacities is initially presented. This is then used to evaluate the dynamic response of nine different TLP geometries when supporting the NREL1 5MW baseline wind turbine model. Numerical simulations are carried out using the marine engineering software tool ANSYS Aqwa©. The work provides an insight on how TLP structures supporting wind turbines may be optimised to facilitate the integration of the proposed CAES concept. It is shown that it is technically feasible to integrate CAES capacities on the order of Megawatt-Hours within TLP structures without compromising the stability of the floating system; although this would involve a substantial increase in the total structure weight.


2020 ◽  
Vol 34 (5) ◽  
pp. 608-620 ◽  
Author(s):  
Long Meng ◽  
Yan-ping He ◽  
Yong-sheng Zhao ◽  
Jie Yang ◽  
He Yang ◽  
...  

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