ROSCO Toolbox - Relationship Between Integral Gain & Damping of Fore-Aft Mode

Wind & Water Controls
1

Hi,

Is there an analytical relationship between the integral gain on the fore-aft damper and the damping of the fore-aft mode in the ROSCO controller? I’m trying to reduce tower-fatigue.

Best wishes,
Sam

2

Hi Sam,
Ervin Bossanyi (amongst others) has proposed a simple analytical relationship:
[url]https://onlinelibrary.wiley.com/doi/abs/10.1002/we.95[/url]

For the tower fore-aft damping control, the FA_KI term is multiplied times a high-pass filtered integrated tower-top fore-aft signal and added to the standard collective pitch command.

Additionally, you could use the “floating feedback” terms to achieve a similar goal. The only difference between the two is the filter for the feedback signals. The tower-top motion signal that Fl_Kp is multiplied by is low-pass filtered by the filter defined by Fl_CornerFreq and is notch filtered by the filter defined by the notch-filter parameters.

Best,
Nikhar

3

Hi Nikhar,

Thanks very much, think I’ve got it working now.

Best,
Sam