Search found 40 matches

by Sina.Ameli
Tue Nov 05, 2019 6:55 am
Forum: Controls
Topic: Power Coefficient
Replies: 3
Views: 145

Re: Power Coefficient

Dear Dr. Jonkman, Thanks for your prompt response. In what situations CP is negative? For instance, is it possible when we have a sudden drop in the wind speed creating a negative torque and finally a negative power coefficient, i.e the wind turbine behaves like a motor (propeller)? Thanks, Best reg...
by Sina.Ameli
Mon Nov 04, 2019 5:59 pm
Forum: Controls
Topic: Power Coefficient
Replies: 3
Views: 145

Power Coefficient

Dear Dr. Jonkman,
In wind turbines, is it possible that CP (Power Coefficient) becomes negative sometimes in region 3?
Thanks,
Best regards,
Sina
by Sina.Ameli
Tue Oct 01, 2019 8:37 am
Forum: Controls
Topic: Power coefficient/Aerodynamic torque
Replies: 12
Views: 355

Re: Power coefficient/Aerodynamic torque

Dear Dr. Jonkman,
Thanks again for your prompt response. I used FAST 8 and Aerodyn v15.03!
Best regards,
Sina
by Sina.Ameli
Mon Sep 30, 2019 2:43 pm
Forum: Controls
Topic: Power coefficient/Aerodynamic torque
Replies: 12
Views: 355

Re: Power coefficient/Aerodynamic torque

Dear Dr. Jonkman, Thanks for your reply and online supports. Let's discuss a little analytically. I plotted the power coefficient (CP) in the closed-loop system when the wind speed is below the rated value (10m/s) with the TI around 25%, and the controller tries to regulate the rated generator speed...
by Sina.Ameli
Mon Sep 30, 2019 7:55 am
Forum: Controls
Topic: Power coefficient/Aerodynamic torque
Replies: 12
Views: 355

Re: Power coefficient/Aerodynamic torque

Dear Dr. Jonkman, Thanks for your prompt response. So far, you have sent me several files including "openfast-master", and "r-test". Now, I am a little confused. The tests located in a different place with different names, while the "Run_OpenLoop.m" asks me for "Ce...
by Sina.Ameli
Sun Sep 29, 2019 10:14 pm
Forum: Controls
Topic: Power coefficient/Aerodynamic torque
Replies: 12
Views: 355

Re: Power coefficient/Aerodynamic torque

Dear Dr. Jonkman, Thanks for your prompt response and sending me those links. Regarding the openfast-master file, when I run the "Run_OpenLoop.m" I get this error: Error using Run_OpenLoop (line 30) Error reported by S-function 'FAST_SFunc' in 'OpenLoop/FAST Nonlinear Wind Turbine/S-Functi...
by Sina.Ameli
Fri Sep 27, 2019 8:23 am
Forum: Controls
Topic: Power coefficient/Aerodynamic torque
Replies: 12
Views: 355

Re: Power coefficient/Aerodynamic torque

Dear Dr. Jonkman, Thanks for your reply. I made those signals output but when I run the "Run_OpenLoop.m" for test 24, it gives me this error: Error using Run_OpenLoop (line 30) Error reported by S-function 'FAST_SFunc' in 'OpenLoop/FAST Nonlinear Wind Turbine/S-Function': FAST_Solution:FAS...
by Sina.Ameli
Wed Sep 25, 2019 7:41 am
Forum: Controls
Topic: Power coefficient/Aerodynamic torque
Replies: 12
Views: 355

Re: Power coefficient/Aerodynamic torque

Dear Dr. Jonkman, Thanks for your prompt response. Actually I have two questions. 1- I cannot see any "RtAeroMxh" ,in the OutList in matlab, which lists 99 output parameters for test 24 in FAST 8. You mentioned this is the output of AeroDyn v.15. Where are its output located to enter them ...
by Sina.Ameli
Tue Sep 24, 2019 9:45 pm
Forum: Controls
Topic: Power coefficient/Aerodynamic torque
Replies: 12
Views: 355

Power coefficient/Aerodynamic torque

Dear Dr. Jonkman, I need the power coefficient or aerodynamic torque output related to the 5MW offshore WT. Could you tell me what are the outputs for them in the outlist in Matlab? In some of messages I found out that RotCp is the output for power coefficient but I couldn't see it in the list of ou...
by Sina.Ameli
Fri Feb 22, 2019 9:05 am
Forum: Controls
Topic: Coefficients of 5MW WT
Replies: 11
Views: 1887

Re: Coefficients of 5MW WT

Dear Dr. Jonkman,

Thank you so much for clarifying the issue.

Best regards,
Sina
by Sina.Ameli
Thu Feb 21, 2019 8:14 pm
Forum: Controls
Topic: Coefficients of 5MW WT
Replies: 11
Views: 1887

Re: Coefficients of 5MW WT

Dear Dr. Jonkman, Thanks for your prompt reply. Regarding my first question, yes, having it simulated, the transient response Wg was not equal to Ngear times Wr but for the steady state response generator speed is equal to gear ratio times rotor speed as it is in the simulation. My second question w...
by Sina.Ameli
Thu Feb 21, 2019 2:29 pm
Forum: Controls
Topic: Coefficients of 5MW WT
Replies: 11
Views: 1887

Re: Coefficients of 5MW WT

Dear Dr. Jonkman, I have two questions about the 5MW wind turbine modeled by FAST. First, does FAST modeled torsion angle that is located in the formula I put above? I realized that in FAST (test 18) Wg=Ng*Wr assuming that there is no speed change in shafts. (It seems it only considers the steady st...
by Sina.Ameli
Fri Feb 15, 2019 7:13 am
Forum: Controls
Topic: Coefficients of 5MW WT
Replies: 11
Views: 1887

Re: Coefficients of 5MW WT

Dear Dr. Jonkman,

Thank you so much for clarifying the issue and introducing the references.

Best regards,
Sina
by Sina.Ameli
Thu Feb 14, 2019 6:25 pm
Forum: Controls
Topic: Coefficients of 5MW WT
Replies: 11
Views: 1887

Re: Coefficients of 5MW WT

Dear Dr. Jonkman, Thanks again for your reply. As I understood, since Fast 8 gives a Jacobians matrix, if I divide the equations by those moments, I can calculate each coefficient using those moments. How can I get the Jacobians matrix using Fast 8? Is this matrix generated in Matlab? What is the pr...
by Sina.Ameli
Thu Feb 14, 2019 2:59 pm
Forum: Controls
Topic: Coefficients of 5MW WT
Replies: 11
Views: 1887

Re: Coefficients of 5MW WT

Dear Dr. Jonkman,

Thanks for your reply that is as always with celerity. I am using Fast 8, my question is that whether I need to switch to Fast 7 for linearization or not to attain those coefficients?

Best regards,
Sina

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