Hello,
I am using the WindPACT models as a baseline for swept blade studies. I notice that the WindPACT model that comes with the FAST archive does not achieve 1500 kW. This is due to the rated torque and speed settings, which did not include the generator efficiency (rated gen power comes out 1400 kW). When I tried to crank the rated torque up, I noticed that the slip from the k*omega^2 curve to rated torque averages out to 1400 kW in normal turbulence. Did this problem occur in the WindPACT studies, or am I missing something? I did not notice anything in the WindPACT reports, and I do not have current contact information for Hansen and Malcolm (assumed retired in some exotic location, like Reno Hilton).
Thanks for the help,
Dear Scott,
I’m not sure I follow you. The WindPACT 1.5-MW model supplied with the FAST archive employs the simple variable-speed (VS) control model (VSContrl = 1). When the turbine is operating at or above rated, the key VS parameters are set as follows:
VS_RtGnSp = 1800.0 rpm (Rated generator speed)
VS_RtTq = 8376.58 Nm (Rated generator torque)
GenEff = 95% (Generator efficiency)
Thus,
Mechanical Power = VS_RtGnSpVS_RtTq = 1.579 MW
Electrical Power = VS_RtGnSpVS_RtTq*GenEff = 1.5 MW
So, as long as the wind speed is high enough to produce rated torque at rated speed, the machine should generate 1.5 MW.
Best regards,
Hi Jason,
The models I have (such at “test11” in CertTest folder) has:
7957.75 VS_RtTq, and
0.002456 VS_Rgn2K
so therefore it was not reaching 1500 kW. I was wondering if there was a reason for this. What is the VS_Rgn2k constant for your model? I’m curious because to adjust this so that k*omega_rated^2 = VS_RtTq places the turbine off of optimal TSR=7.
Thanks,
Hi Jason,
A better reply from me is that it seems we have different input files for the WindPACT model. Would you please either send me your input file or tell me where it resides in the FAST download archive.
Thanks,
Dear Scott,
I found the problem. I looked through the FAST change log and noticed that in FAST v6.01a-jmj, dated 29-Jul-2005, I changed the VS control constants of the WindPACT model to correct for the error you are reporting. In older versions of FAST, the VS control constants were specified incorrectly such that the model would not produce 1.5 MW. But in FAST v6.01-jmj and newer (including the current version of FAST downloadable from the website), Test11.fst, Test12.fst, and Test13.fst from the CertTest folder all list the parameters I refer to in my previous post. Simply download the latest version to get the “correct” model.
Best regards,
Jason,
Thank you for looking into this. I will download the new version.
Regards,