Wishes for FAST 8.x

Wind & Water Computer-Aided Engineering Software Tools
1

Hi FAST-developers,

in the announcement of FAST 7.02 [url]Software Releases] I read about the FAST 8.x framework, which is currently under development at NREL. I have several ideas of what features FAST 8.x should provide in my point of view, however I have not found any information on which features NREL is currently implementing. Therefore I want to list my wishes for FAST 8.x:

  • An output for the mean wind speed over the rotor disc should be added

  • Blade acceleration outputs should contain gravitation, i.e. the output should reflect what an inertial measurement unit would measure

  • The FAST configuration file (fst) should be split in a file containing only information on the turbine (geometry, masses, links to tower, blade, etc), a file for simulation settings (time end, DT, etc) and all information on special maneuver should be removed.

  • All code for special maneuvers should be removed from FAST and should be implemented in a separate discon-DLL with a configuration file for the DLL containing all the maneuver infos

  • FAST should use the discon-DLL as standard interface to controllers.

  • We extended FAST to load several dison-DLLs and to call them all in sequence in each time step. By that FAST first writes all information from the turbine to avrSWAP. Then the first DLL adds measurement error to avrSWAP (noise, Offset). Next the turbine controller-DLL calculates Torque + Pitch based on the information in avrSWAP. Last, a disconDLL is called which contains a pitch actor model. This model takes the reference pitch values from avrSWAP and writes the current pitch actuator pitch position back to avrSWAP. Last, FAST takes pitch and torque from avrSWAP and simulates the next time step. I think in the same way all override-maneuvers could be added as a separate DLL. I hope you understand the idea behind this.

It would be great, if some of my ideas/whishes would be implemented in FAST 8.x

Best regards
Felix

2

Dear Felix,

Thank you for your suggestions on FAST improvements. You’ll be happy to know that most of these suggestions are already on our “to-do” list (at least in some form), altough not all of them will be included in the first release of FAST v8 (the version of FAST in the new modularization framework).

Please note that we plan to take the existing control and electrical drive logic from FAST and move it to a new module called ServoDyn. As part of this, the input data currently in the FAST primary input file will be moved to a new input file for ServoDyn. The ServoDyn module will allow for GH Bladed-style DLL controllers (DISCON.dll) as one of the standard (built-in) options instead of as a compile-time option like it is now. While the DISCON.dll will be available, some of the features you’ve requested, such as measurement error and actuator response, we plan to include directly within ServoDyn at some point.

Best regards,