Search found 14 matches

by Lei.Duan
Fri May 02, 2014 1:25 am
Forum: Controls
Topic: estimator of effective/relative wind velocity
Replies: 3
Views: 5837

estimator of effective/relative wind velocity

Hi, all. I am working on the controller for offshore floating wind turbines in Region 2 (between cut-in and rated velocity), and using FAST in Simulink. I would like to have an estimator for obtaining the effective/relative wind velocity (considering platform's moving...) at hub height. Therefore, I...
by Lei.Duan
Sat Apr 19, 2014 4:39 am
Forum: Controls
Topic: Blade pitch control
Replies: 26
Views: 11355

Re: Blade pitch control

Dear Jason,
Thanks for your reply.
I also think the pitch actuator mentioned in Section 7.4 is too fast.

Anyway, thank you very much.

Best regards,
Lei DUAN
by Lei.Duan
Wed Apr 16, 2014 9:18 pm
Forum: Controls
Topic: Blade pitch control
Replies: 26
Views: 11355

Blade pitch control

Hi, all. Now, I am working on the blade pitch control of 5-MW baseline wind turbine. I would like to use a simple model of the blade pitch actuator as dot(B)=-1/tau*B+1/tau*Bd where B is the blade pitch angle; tau is the time constant; and Bd is the desired blade pitch angle as a command. Could anyo...
by Lei.Duan
Sun Dec 15, 2013 12:07 am
Forum: Controls
Topic: State of linearized model, rotor's speed
Replies: 20
Views: 11791

Re: State of linearized model, rotor's speed

Dear Jason,
Thank you very much.
I will follow your suggestion and have a try.

Best wishes,
Lei DUAN
by Lei.Duan
Thu Dec 12, 2013 4:46 am
Forum: Controls
Topic: State of linearized model, rotor's speed
Replies: 20
Views: 11791

Re: State of linearized model, rotor's speed

DearJason, Thank you very much. I checked the eigenvalues of the A matrix by using the parameters you provided. They seemed reasonable. Have you published the Jr somewhere? I need to quote it. Also, I ran FAST to get the Bg and Omega(Torq=zero), but I did not know the appropriate settings of DOFs an...
by Lei.Duan
Wed Dec 11, 2013 4:49 am
Forum: Controls
Topic: State of linearized model, rotor's speed
Replies: 20
Views: 11791

Re: State of linearized model, rotor's speed

Dear Jason, Thanks for your reply, and it help me much. Also, I am following a book to build a state-space model for control by using the torsion angle(q_DrTrDOF), the rotor speed (qdot_GenDOF+qdot_DrTrDOF), and the generator speed (qdot_GenDOF) as the states. The A matrix is shown as A=[ 0 , 1 , -1...
by Lei.Duan
Sun Dec 08, 2013 2:13 am
Forum: Controls
Topic: State of linearized model, rotor's speed
Replies: 20
Views: 11791

State of linearized model, rotor's speed

Hi, I met a problem of controller design. I have read the technical report “Modern Control Design for Flexible Wind Turbines”, and been interested in the models (1-state, 3-state, 7-state, and 9-state model) mentioned in it. Among these models, they all use the rotor’s speed as a state. I would like...
by Lei.Duan
Tue Jun 04, 2013 5:31 pm
Forum: Rotor Aerodynamics
Topic: Relative wind speed
Replies: 8
Views: 9805

Re: Relative wind speed

Dear Jason,
Thank a lot for your answer. It helps me much.

Best wishes,
Lei DUAN
by Lei.Duan
Tue Jun 04, 2013 8:23 am
Forum: Rotor Aerodynamics
Topic: Relative wind speed
Replies: 8
Views: 9805

Re: Relative wind speed

Dear Lei, Yes, AeroDyn will use the local relative wind speed to calculate the aerodynamic load separately for each node (different for every node of every blade). While this approach may violate assumptions in the original momentum theory, it has been shown to give reasonable results when compared...
by Lei.Duan
Wed May 22, 2013 3:25 am
Forum: Rotor Aerodynamics
Topic: Rotor aerodynamics while OFWT is moving
Replies: 5
Views: 8419

Re: Rotor aerodynamics while OFWT is moving

Dear Jason,
Thanks a lot for your reply.
I am sorry for the unclear questions. However, your answer is quite helpful.

Best wishes,
Lei DUAN
by Lei.Duan
Wed May 22, 2013 2:14 am
Forum: Rotor Aerodynamics
Topic: Relative wind speed
Replies: 8
Views: 9805

Re: Relative wind speed

Hi, Jason.
Thank you very much for the reply.


Best wishes,
Lei DUAN
by Lei.Duan
Tue May 21, 2013 4:47 am
Forum: Rotor Aerodynamics
Topic: Rotor aerodynamics while OFWT is moving
Replies: 5
Views: 8419

Re: Rotor aerodynamics while OFWT is moving

Dear Lei, While I agree with Marshall, there is one subtlety that you should be aware of. When AeroDyn computes the relative wind speed for use in the dynamic pressure and angle of attack calculations, the computed induction factor applies only to the free stream wind speed, not the relative wind s...
by Lei.Duan
Tue May 21, 2013 3:40 am
Forum: Rotor Aerodynamics
Topic: Relative wind speed
Replies: 8
Views: 9805

Re: Relative wind speed

Dear Omid, FAST will use the relative wind speed in this case. I general, FAST takes the structural position/orientation/velocity of each aerodynamic analysis node (based on all structural motions, including rigid-body motions and beam deflections) and sends the values to AeroDyn. AeroDyn uses thes...
by Lei.Duan
Wed Oct 31, 2012 9:19 am
Forum: Rotor Aerodynamics
Topic: Rotor aerodynamics while OFWT is moving
Replies: 5
Views: 8419

Rotor aerodynamics while OFWT is moving

Hi, I am a freshman in aerodynamics of wind turbines. Now, I am writing a simple model of offshore floating wind turbine (OFWT) in MATLAB for control design. I would like to calculate the aerodynamics by using the BEM model recommended by “AeroDyn Theory Manual”. Compared with land-based wind turbin...

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