scholarly journals Modern methods for investigating the stability of a pitching floating platform wind turbine

2017 ◽  
Vol 2 (2) ◽  
pp. 671-683 ◽  
Author(s):  
Matthew Lennie ◽  
David Marten ◽  
George Pechlivanoglou ◽  
Christian Navid Nayeri ◽  
Christian Oliver Paschereit
Keyword(s):  
Wind Turbine ◽  
Turbine Rotor ◽  
Test Case ◽  
Floating Platform ◽  
Platform Motion ◽  
The Stability ◽  
The Many ◽  
New Formulation ◽  
Key Steps ◽  
Lifting Line

Abstract. The QBlade implementation of the lifting-line free vortex wake (LLFVW) method was tested in conditions analogous to floating platform motion. Comparisons against two independent test cases using a variety of simulation methods show good agreement in thrust forces, rotor power, blade forces and rotor plane induction. Along with the many verifications already undertaken in the literature, it seems that the code performs solidly even in these challenging cases. Further to this, the key steps are presented from a new formulation of the instantaneous aerodynamic thrust damping of a wind turbine rotor. A test case with harmonic platform motion and collective blade pitch is used to demonstrate how combining such tools can lead to a better understanding of aeroelastic stability. A second case demonstrates a non-harmonic blade pitch manoeuvre showing the versatility of the instantaneous damping method.

scholarly journals Modern methods for investigating the stability of a pitching floating platform wind turbine

2016 ◽  
Author(s):  
Matthew Lennie ◽  
David Marten ◽  
George Pechlivanoglou ◽  
Christian Navid Nayeri ◽  
Christian Oliver Paschereit
Keyword(s):  
Wind Turbine ◽  
Turbine Rotor ◽  
Test Case ◽  
Floating Platform ◽  
Platform Motion ◽  
The Stability ◽  
The Many ◽  
New Formulation ◽  
Key Steps ◽  
Lifting Line

Abstract. The QBlade implementation of the Lifting Line Free Vortex Wake method(LLFVW) was tested in conditions analogous to floating platform motion. Comparisons against two independent test cases, using a variety of simulation methods show excellent agreement in thrust forces, rotor power, blade forces and rotor plane induction. Along with the many verifications already undertaken in literature, it seems that the code performs solidly even in these challenging cases. Further to this, the key steps are presented from a new formulation of the instantaneous aerodynamic thrust damping of a wind turbine rotor. A test case with harmonic platform motion and collective pitch is used to demonstrate how combining such tools can lead to better understanding of aeroelastic stability.

scholarly journals Modern methods for investigating the stability of a pitching floating platform wind turbine

2016 ◽  
Vol 753 ◽  
pp. 082012 ◽  
Author(s):  
Matthew Lennie ◽  
David Marten ◽  
George Pechlivanoglou ◽  
Christian Navid Nayeri ◽  
Christian Oliver Paschereit
Keyword(s):  
Wind Turbine ◽  
Floating Platform ◽  
Modern Methods ◽  
The Stability

scholarly journals Optimum Power Output Control of a Wind Turbine Rotor

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
S. Wijewardana ◽  
M. H. Shaheed ◽  
R. Vepa
Keyword(s):  
Equilibrium Point ◽  
Wind Turbine ◽  
Power Output ◽  
Turbine Blades ◽  
Turbine Rotor ◽  
Power Coefficient ◽  
Output Control ◽  
The Stability ◽  
Lift And Drag ◽  
Wind Turbine Rotor

An active and optimum controller is applied to regulate the power output from a wind turbine rotor. The controller is synthesized in two steps. The first step defines the equilibrium operation point and ensures that the desired equilibrium point is stable. The stability of the equilibrium point is guaranteed by a control law that is synthesized by applying the methodology of model predictive control (MPC). The method of controlling the turbine involves pitching the turbine blades. In the second step the blade pitch angle demand is defined. This involves minimizing the mean square error between the actual and desired power coefficient. The actual power coefficient of the wind turbine rotor is evaluated assuming that the blade is capable of stalling, using blade element momentum theory. This ensures that the power output of the rotor can be reduced to any desired value which is generally not possible unless a nonlinear stall model is introduced to evaluate the blade profile coefficients of lift and drag. The relatively simple and systematic nonlinear modelling and MPC controller synthesis approach adopted in this paper clearly highlights the main features on the controller that is capable of regulating the power output of the wind turbine rotor.

scholarly journals Effect of Platform Motion on Aerodynamic Performance and Aeroelastic Behavior of Floating Offshore Wind Turbine Blades

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2519 ◽  
Author(s):  
Kim ◽  
Kwon
Keyword(s):  
Wind Turbine ◽  
Bending Moment ◽  
Turbine Rotor ◽  
Aerodynamic Performance ◽  
Rotor Blades ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Floating Offshore Wind Turbine ◽  
Platform Motion ◽  
Aerodynamic Loads

In the present study, a numerical framework for predicting the aerodynamic performance and the aeroelastic behavior of floating offshore wind turbine rotor blades involving platform motion was developed. For this purpose, the aerodynamic and structural analyses were conducted simultaneously in a tightly coupled manner by exchanging the information about the aerodynamic loads and the elastic blade deformations at every time step. The elastic behavior of the turbine rotor blades was described by adopting a structural model based on the Euler-Bernoulli beam. The aerodynamic loads by the rotor blades were evaluated by adopting a blade element momentum theory. The numerical simulations were conducted when the platform of the wind turbine independently moves in each of the six degrees-of-freedom directions consisting of heave, sway, surge, roll, pitch, and yaw. It was observed that flexible blades exhibit complicated vibratory behaviors when they are excited by the aerodynamic, inertia, and gravitational forces simultaneously. It was found that the load variation caused by the platform surge or pitch motion has a significant influence on the flapwise and torsional deformations of the rotor blades. The torsional deformation mainly occurs in the nose-down direction, and results in a reduction of the aerodynamic loads. It was also found that the flapwise root bending moment is mainly influenced by the platform surge and pitch motions. On the other hand, the edgewise bending moment is mostly dictated by the gravitational force, but is not affected much by the platform motion.

scholarly journals Baseline Design of the Deep Turbine Installation-Floating, a New Floating Wind Concept

2019 ◽  
Author(s):  
Jordi Serret ◽  
Tahsin Tezdogan ◽  
Tim Stratford ◽  
Philipp R. Thies ◽  
Vengatesan Venugopal
Keyword(s):  
Wind Turbine ◽  
Natural Frequencies ◽  
International Electrotechnical Commission ◽  
Preliminary Design ◽  
Floating Platform ◽  
Hydrodynamic Properties ◽  
Baseline Design ◽  
Design Load ◽  
The Stability ◽  
Turbine Installation

Abstract This paper presents the preliminary design of the Deep Turbine Installation-Floating (DTI-F) concept. The DTI-F concept is a hybrid spar buoy-based floating offshore substructure capable of supporting a 7MW wind turbine with the uniqueness of being able to raise and lower the tower and nacelle, which simplifies construction, installation, maintenance, and decommissioning. A relevant subset of design load cases (DLCs) derived from the International Electrotechnical Commission (ICE) standards is simulated with NREL-FAST software, and the aero-elastic loads are used for the structural assessment. The paper presents the principal dimensions and crucial hydrostatic and hydrodynamic properties. The floating platform with three different mooring configurations is designed using ANSYS AQWA software, and the design is validated with experiments in laboratory conditions. The paper evaluates the design regarding the natural frequencies and the stability of the platform for a chosen site off the Scottish coast. Further, a novel construction method, the materials chosen for the construction, and the installation and assembly processes are also outlined.

Calculation method of efficiency factor in Alford's force

2006 ◽  
Vol 220 (2) ◽  
pp. 169-177 ◽  
Author(s):  
X. J. Ding ◽  
Y. L. Yang ◽  
W Chen ◽  
S. H. Huang ◽  
C. G. Zheng
Keyword(s):  
Stability Analysis ◽  
Physical Meaning ◽  
Theoretical Foundation ◽  
Turbine Rotor ◽  
Current Theory ◽  
Efficiency Factor ◽  
Flow Parameters ◽  
Calculation Results ◽  
The Stability ◽  
New Formulation

The mechanism of gas excitation for wheel eccentricity and to calculate Alford's force are introduced. On the basis of the blade-and-flow parameters a new formulation is derived and validated. The calculation results are consistent with current theory and experimental conclusions. The physical meaning of the ranges of numerical values of the efficiency factor are discussed. This gets rid of the difficulty of selecting the efficiency factor in Alford's formulation and lays a theoretical foundation for the stability analysis to increase turbine rotor stability.

A Method for Modeling of Floating Vertical Axis Wind Turbine

2013 ◽  
Author(s):  
Kai Wang ◽  
Torgeir Moan ◽  
Martin Otto Laver Hansen
Keyword(s):  
Wind Turbine ◽  
Dynamic Equilibrium ◽  
Vertical Axis ◽  
Economic Feasibility ◽  
Vertical Axis Wind Turbine ◽  
Floating Platform ◽  
Time Step ◽  
Mooring Lines ◽  
Platform Motion ◽  
Novel Concept

It is of interest to investigate the potential advantages of floating vertical axis wind turbine (FVAWT) due to its economical installation and maintenance. A novel 5MW vertical axis wind turbine concept with a Darrieus rotor mounted on a semi-submersible support structure is proposed in this paper. In order to assess the technical and economic feasibility of this novel concept, a comprehensive simulation tool for modeling of the floating vertical axis wind turbine is needed. This work presents the development of a coupled method for modeling of the dynamics of a floating vertical axis wind turbine. This integrated dynamic model takes into account the wind inflow, aerodynamics, hydrodynamics, structural dynamics (wind turbine, floating platform and the mooring lines) and a generator control. This approach calculates dynamic equilibrium at each time step and takes account of the interaction between the rotor dynamics, platform motion and mooring dynamics. Verification of this method is made through model-to-model comparisons. Finally, some dynamic response results for the platform motion are presented as an example for application of this method.

First Iteration Design of the Flotant Concept

2021 ◽  
Author(s):  
Jordi Serret ◽  
Bernardo Kahn ◽  
Bruce Cavanagh ◽  
Patricia Lorente ◽  
Remy Pascal ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Open Source ◽  
Elastic Behaviour ◽  
International Electrotechnical Commission ◽  
Floating Platform ◽  
Horizon 2020 ◽  
Research And Innovation ◽  
Seakeeping Performance ◽  
Floating System ◽  
The Stability

Abstract This paper presents the first iteration design of the Flotant concept developed within the framework of a Cooperation Research Project funded by the European Union’s Horizon 2020 research and innovation programme. The Flotant concept is a hybrid concrete-plastic barge-type floating offshore substructure holding a 12MW wind turbine with the singularity of getting floatability by using plastic foam material fitted within the floater substructure. The INS12MW generic wind turbine, an upscaling exercise based on the DTU10MW reference wind turbine, is presented and simulated using open-source certified aeroelastic code. The floating platform and the mooring system are designed for two different sites, West of Barra and South East of Gran Canaria island. The principal dimensions are presented along with the hydrostatic and hydrodynamic properties of the floating system. A relevant subset of design load cases derived from International Electrotechnical Commission and Det Norske Veritas standards was simulated using an open-source aeroelastic code (NREL FAST) to check the coupled aero-hydro-elastic behaviour of the floating system and to generate the required load-matrix for the structural assessment of the different components. The evaluation of the design includes the seakeeping performance, the stability of the floating platform and the global performance analysis for the abovementioned sites. It demonstrates the technology developed within the Flotant project is feasible even in rough conditions like the ones in the West of Barra site.

scholarly journals Methods of Increasing the Stability of Speed Rotation of Wind Turbine Rotor

2019 ◽  
Vol 21 (4) ◽  
pp. 166
Author(s):  
V I Buyalsky ◽  
N M Schaytor
Keyword(s):  
Wind Turbine ◽  
Turbine Rotor ◽  
Speed Rotation ◽  
The Stability ◽  
Wind Turbine Rotor

Проведен анализ и исследование методов повышения стабильности и частоты вращения современных ветроустановок в процессе производства электроэнергии. Обоснована необходимость уменьшения динамических нагрузок и улучшения показателей надежности в условиях неполной информации о характеристиках метеорологических и электроэнергетических условий, изменяющихся во времени. Усовершенствована математическая модель процесса производства электроэнергии ВЭУ, отличающаяся тем, что метеопараметр, определяющий характер зависимости угловой скорости ротора ветроколеса от скорости ветра и угла положения лопасти, выбирается с возможностью заблаговременного определения изменения частоты вращения ветроколеса, что способствует учету динамических свойств системы для повышения оперативности принятия управляющих решений при переменных характеристиках метеорологических условий. При этом наличие коэффициента в предложенной формуле обеспечивает понижение кубической степени метеопараметра до единицы, что дает возможность получить линейную зависимость скорости вращения ротора в соответствии с изменением внешней среды. Предложен метод подготовки системы к внешним возмущающим воздействиям, содержащий своевременную установку угла питча лопасти в соответствии с оценкой скорости воздушного потока и потребляемой мощности, учетом инерционности системы и времени изменения положения лопастей, что позволяет учитывать динамические особенности работы системы. Приведена система линейных дифференциальных уравнений для автоматического регулирования с учетом влияния скорости ветра, мощности потребляемой электроэнергии и времени запаздывания по регулированию. Разработана модифицированная математическая модель процесса производства электроэнергии ветроэнергетической установкой с возможностью заблаговременного определения изменения частоты вращения ветротурбины.

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