Dear Jason,
thank you for your fast reply.
I scaled appropriate geometry, mass and stiffness terms as you scaled. For the purpose of the discussion let’s assume they are correct and I can move on to changing parameters in DISCON controller. The problem I am facing a problem computing values of Ki and Kp.
If I understood correctly, to get them I need sensitivity of aerodynamic power to the rotor collective blade-pitch angle ∂P/∂θ (I assumed natural frequency ω_φn and damping ratio ζ_φ to be 0.6 rad/s and 0.6-0.7 respectively).
In Table 7.1 (page 23, “Definition of a 5MW Reference Wind Turbine…”) you presented result for wind speed range from 11.4 to 25 m/s. Was the corresponding pitch angle found by simply running FAST simulation for different angles and selecting the one which yielded mechanical power the closest to rated?
You described the whole linearization procedure to obtain values of sensitivity in the ''Gain Scheduling" post (Gain Scheduling). I followed your procedure, I cannot find anywhere the D-Trnsmt matrix you mentioned. I opened the *.lin file with MBC matlab script called GetMats.m, then run cce.m script as well.
I am completely lost and would greatly appreciate if you could explain me the solution to the problem step-by-step. How the linearization for this purpose should be performed. I even downloaded the FAST v6.01 with AeroDyn v12.58 modified to apply frozen wake during linearization, however newer input files seem not to be compatible with the app.
Thank you in advance!
Regards,
Sebastian Dziomdziora