# Cp (power coefficient) of WindPact 1.5 Mw turbine

I am trying to run FAST simulations on the included WindPact 1.5 MW turbine. For region 2 control, I am trying to implement Lucy Pao’s method of tracking maximum Cp(power coefficient). I went through WindPact study papers but couldn’t find maps of power coefficient as a function of tip-speed ratio and pitch angle. Does there exist such a map of Cp for WindPact 1.5 Mw turbine? or at least the maximum value of Cp and the associated blade pitch angle and tip-speed ratio?

Thanks

Dear Dee,

The 1.5-MW turbine model we supply in the FAST CertTest is a model of the WindPACT 1.5-MW baseline, as documented in this report: nrel.gov/docs/fy06osti/32495.pdf. The report states that the rotor for this turbine was designed for a maximum power coefficient (Cpmax) of 0.50 at an optimal tip-speed ratio (TSR) of 7.0 and an optimal blade-pitch angle (thetap) of 2.6 degrees. I’ve not ran this model myself much, it’s been a very long time since of I have, and I don’t recall if the model produces these values exactly. (They should be close.) If you need more data than this (like the complete Cp versus TSR/thetap curve), you can run your own simulations to derive the data you seek.

Best regards,

Thanks Jason,
Knowing max. Cp will certainly help. I just wanted to know if somebody has already generated Cp maps for this turbine before I start doing it.

Dear Dr.Jonkman
Hello
I have tried for 1.5 MW, but I found the parameters a little different:
at wind speed = 6 m/s and fulfilling maximum power point tracking//
Rotor speed = 1.446 rad/s
Cp = 0.625 instead of 0.5
TSR = 8.435 instead of 7
beta = 0;

What’s the problem? Do you think it is unreasonable ?

Best Regards

Dear Amirhossein,

I’m not sure what process you used to derive these results, but they don’t look correct. Indeed, you are showing that the max Cp exceeds the Betz limit. My guess is that your solution does not represent a steady-state condition.

Best regards,

Thanks dear

you are trust, but -on the other hand- any kind of winds includes turbulence and transient like what I attached here:
My problem is mainly about the region I point with red color.

Sincerely

Dear Amirhossein,

We’ve had a discussion on this forum regarding how FAST calculates RotCp. Please see the forum topic found here: http://forums.nrel.gov/t/betz-law-and-rotcp/259/1. Hopefully this clarifies things a bit.

If you are interested in deriving the power coefficient curve (say as a function of TSR or pitch), you should ensure that the solution is in a steady-state condition. You should use steady/uniform wind input, not turbulent wind input.

Best regards,