Rockwell Automation 20P PowerFlex Digital DC Drive - Manual (Page 304)

304 Rockwell Automation Publication 20P-UM001I-EN-P - February 2013
Appendix C Application Notes
Fine Tuning the Field Current Regulator
The procedure below is used for drives that use constant torque and power
(mixed armature and field regulation). In these cases it is necessary to configure
the field converter according to this method.
Follow the procedure below to fine tune and optimize the field current regulator:
1. Configure the following parameters:
❏ Set Par 467 [Max Fld Curr Pct] = 100% of the field rated current of the
connected motor
❏ Set Par 468 [Min Fld Curr Pct] = 0
❏ Set Par 91 [Fld Reg Kp] = 0.00
❏ Set Par 92 [Fld Reg Ki] = 0.00
2. Measure the field current using an analog output by setting:
❏ Par 66 [Anlg Out1 Sel] = 18 “Fld Current”
❏ Par 67 [Anlg Out2 Sel] = 24 “Field Ref ”
3. Configure the following parameters:
❏ Set Par 497 [Field Reg Enable] = 1 “Enabled” (default)
❏ Set Par 469 [Field Mode Sel] = 1 “Field Weaken”
❏ Set Par 498 [Force Min Field] = 1 “Enabled”
4. Configure the following Test Generator parameters:
❏ Set Par 58 [TstGen Output] = 3 “Field Ref ”
❏ Set Par 60 [TstGen Amplitude] = 70% of the field rated current of the
motor (this setting allows the system overshoot).
IMPORTANT In most cases motors with a direct current and an independent excitation work
with a constant field (Par 469 [Field Mode Sel] = 0 “Base Speed”). In this case it
is not necessary to optimize the field current or armature voltage regulators.
IMPORTANT Do not issue a “Start” command to the drive during the field current regulator
fine tuning procedure.