Blade pitch control

[Lei.Duan]

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 anyone tell me how to determine the value of tau for such a reference wind turbine?

Thanks in advance.

Best regards
Lei DUAN

[Jason.Jonkman]

Dear Lei DUAN,

Section 7.4 of the NREL 5-MW specifications report describes the characteristics of a very fast blade-pitch actuator: http://www.nrel.gov/docs/fy09osti/38060.pdf. I'll let someone else respond if they know of more realistic values for a 5-MW turbine.

Best regards,

[Lei.Duan]

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

[Jinsong.Liu]

thank you for your prompt response. I get it now!

[Jason.Jonkman]

Dear Jinsong,

As discussed in several papers (e.g.: http://www.nrel.gov/docs/fy08osti/42589.pdf), the control system may have a strong influence on the response of a FOWT and vice-versa. Have you adopted a controller (particularly the pitch-control gains) to work with your floating wind system?

Best regards,

[MohamedYassin.Oukila]

Dear Lei DUAN,

Section 7.4 of the NREL 5-MW specifications report describes the characteristics of a very fast blade-pitch actuator: http://www.nrel.gov/docs/fy09osti/38060.pdf. I'll let someone else respond if they know of more realistic values for a 5-MW turbine.

Best regards,

Dear Jason,

I am currently trying to run the 5-MW NREL onshore using "FAST_v7.02.00d-bjj_AeroDyn_v13.00.02a-bjj_BladedDLLInterface.exe". I want to run the same wind turbine in Bladed. Is DISCON.DLL is the same controller as the one used in the exe mentioned before?
I have to model the pitch actuator in Bladed. Have you found any realistic values for this turbine?

Regards,

[Paul.Fleming]

Hi,

I think I can help on this. DISCON.DLL should be in the Bladed external controller format already so should be the same. I'm not sure there is defined a pitch actuator for this turbine. A reasonable choice though is probably just a first or second order lag.

Paul

[Raivis.Nikitins]

Dear All,

I would like to learn what is the main objective of the blade-pitch process control? Could anyone describe in more detail (possibly using charts) what is happening when PI is used for eroded blades?

Thank you,

Raivis.Nikitins

[Jason.Jonkman]

Dear Raivis,

The main objective of a baseline blade-pitch control system is to regulate the rotor (or generator) speed. See section 7.3 of the NREL 5-MW specifications report for the development of a standard baseline pitch control system: http://www.nrel.gov/docs/fy09osti/38060.pdf.

More advanced pitch control systems may include additional actuation (e.g. independent blade pitch) and additional control objectives (e.g. reducing loads).

If the rotor-blades are eroding, the controller gains may not be as the designer expected and the controller would not perform optimally.

Best regards,

[Raivis.Nikitins]

Thank you, Jason!

I will study the NREL 5-MW specifications report.

Best regards,

Raivis.Nikitins
Adaplab

[zarei.atefe]

Hi everyone
I'm working on individual pitch control and set PCMode to 4 to get the pitch command from the simulink controller but the pitch remains fixed to the final value of 2.6 and does not command the simulink. Where is the problem?
thanks

[Jason.Jonkman]

Dear Zarei,

Are you saying that you running FAST interfaced to Simulink, you've set PCMode=4, but the commands from Simulink are being ignored? Have you enabled the override pitch maneuvers (TPitManS(*), PitManRat(*), BlPitchF(*)), which override the commands from the controller?

Best regards,

[zarei.atefe]

No I did not enable these. I just set PCMODE to 4 and then run the simulation.

[Jason.Jonkman]

Dear Zarei,

And you are running the simulation from Simulink?

Best regards,

[zarei.atefe]

Yes, I'm running from Simulink.