Rockwell Automation PowerFlex series, Руководство пользователя

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PowerFlex Digital DC Drive User Manual - Publication 20P-UM001C-EN-P - July 2008
Application Notes C-31
Fine Tuning the Voltage Regulator in the Field Converter
Important: In most cases, DC motors with 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
regulator of the field current and the regulator of the armature
voltage.
When field weakening occurs, the voltage regulator keeps the armature
voltage at a constant level. The critical point for this regulator is at the
beginning of field weakening, because with the saturation of the motor field
the system requires more consistent changes in the field current in order to
carry out a flux change. Tune the regulator so that the armature voltage
undergoes very small changes.
Important: Before the optimization of the voltage regulator, the speed and
field current regulators must have already been tuned. Refer to
Tune the Current Regulator: on page 2-10 and Fine Tuning the
Field Current Regulator on page C-26 .
1. Configure the following Test Generator parameters:
❏
Set Par 58 [TstGen Output] = 4 “Ramp Ref”
❏
Set Par 59 [TstGen Frequency] = 0.2 Hz
❏
Set Par 60 [TstGen Amplitude] = 10 %
❏
Set Par 61 [TstGen Offset] = to the switching point from the
armature to the field regulation. For example: If Par 162 [Max
Feedback Spd] = 2000 rpm, field weakening starts at 1500 rpm.
Therefore, set Par 61 [TstGen Offset] = 75 %.
2. Measure the field current and the armature voltage using analog outputs 1 and
2, by setting:
❏
Par 66 [Anlg Out1 Sel] = 18 “Fld Current”
❏
Par 67 [Anlg Out2 Sel] = 14 “Motor Volts”
3. Start the drive.
4. Check the armature voltage via analog output 2. After a possible short
oscillation, the voltage should remain constant. Refer to the Field Voltage
Regulator examples below. You can change the Proportional and Integral gains
of the Field Voltage regulator via Pars 493 [Arm Volt Kp] and 494 [Arm Volt Ki].
5. Stop the drive.
6. Set Par 58 [TstGen Output] = 0 “NotConnected”.