Tower velocity feedback filter

ROSCO_toolbox/turbine.py

@@ -193,6 +193,13 @@ def load_from_fast(self, FAST_InputFile,FAST_directory, FAST_ver='OpenFAST',dev_
         self.Ct = RotorPerformance(self.Ct_table,self.pitch_initial_rad,self.TSR_initial)
         self.Cq = RotorPerformance(self.Cq_table,self.pitch_initial_rad,self.TSR_initial)
 
+        # Pull out some floating-related data
+        wave_tp = fast.fst_vt['HydroDyn']['WaveTp'] 
+        try:
+            self.wave_peak_period = 1/wave_tp       # Will work if HydroDyn exists and a peak period is defined...
+        except:
+            self.wave_peak_period = 0.0             # Set as 0.0 when HydroDyn doesn't exist (fixed bottom)
+
     # Load rotor performance data from CCBlade 
     def load_from_ccblade(self,fast):
         '''

ROSCO_toolbox/utilities.py

@@ -439,8 +439,9 @@ def write_param_file(self, turbine, controller, param_file='DISCON.IN', txt_file
         file.write('{:<13.2f}       ! F_LPFCornerFreq	- Corner frequency (-3dB point) in the low-pass filters, [rad/s]\n'.format(turbine.bld_edgewise_freq * 1/4)) 
         file.write('{:<13.2f}       ! F_LPFDamping		- Damping coefficient [used only when F_FilterType = 2]\n'.format(controller.F_LPFDamping))
         file.write('{:<13.2f}       ! F_NotchCornerFreq	- Natural frequency of the notch filter, [rad/s]\n'.format(0.0))
-        file.write('{:<6.1f}{:<13.1f} ! F_NotchBetaNumDen	- Two notch damping values (numerator and denominator, resp) - determines the width and depth of the notch, [-]\n'.format(0.0,0.0))
+        file.write('{:<10.1f}{:<9.1f} ! F_NotchBetaNumDen	- Two notch damping values (numerator and denominator, resp) - determines the width and depth of the notch, [-]\n'.format(0.0,0.0))
         file.write('{:<014.6f}      ! F_SSCornerFreq    - Corner frequency (-3dB point) in the first order low pass filter for the setpoint smoother, [rad/s].\n'.format(controller.ss_cornerfreq))
+        file.write('{:<10.4f}{:<9.4f} ! F_FlCornerFreq    - Corner frequency and damping in the second order low pass filter of the tower-top fore-aft motion for floating feedback control [rad/s, -].\n'.format(turbine.wave_peak_period*2*pi * 0.2, 0.7))
         file.write('\n')
         file.write('!------- BLADE PITCH CONTROL ----------------------------------------------\n')
         file.write('{:<11d}         ! PC_GS_n			- Amount of gain-scheduling table entries\n'.format(len(controller.pitch_op_pc)))
@@ -525,7 +526,8 @@ def write_param_file(self, turbine, controller, param_file='DISCON.IN', txt_file
         file.write('\n')
         file.write('!------- SHUTDOWN -------------------------------------------\n')
         file.write('{:<014.5f}      ! SD_MaxPit         - Maximum blade pitch angle to initiate shutdown, [rad]\n'.format(controller.sd_maxpit))
-        file.write('{:<014.5f}      ! SD_CornerFreq     - Cutoff Frequency for first order low-pass filter for blade pitch angle, [rad/s]'.format(controller.sd_cornerfreq))
+        file.write('{:<014.5f}      ! SD_CornerFreq     - Cutoff Frequency for first order low-pass filter for blade pitch angle, [rad/s]\n'.format(controller.sd_cornerfreq))
+        file.write('\n')
         file.write('!------- Floating -------------------------------------------\n')
         file.write('{:<014.5f}      ! Fl_Kp             - Nacelle velocity proportional feedback gain [s]\n'.format(controller.Kpf))
         file.close()