Parameter and variable descriptions – Rockwell Automation 1557 MEDIUM VOLTAGE AC DRIVE User Manual
Page 98
6-42
PARAMETER AND VARIABLE DESCRIPTIONS
1557-UM050F-EN-P – June 2013
20 Speed Control Variables
Speed Feedback [Speed feedback]
Linear number:
289
Minimum value:
-100.0 Hz
Maximum value:
100.0 Hz
Analog Output Scaling: 1.0 V = 12.8 Hz
This variable is the calculated speed feedback after filtering. The speed feedback is positive for forward
rotation and negative for reverse rotation.
Speed Error [Speed error]
Linear number:
290
Minimum value:
-10.00 Hz
Maximum value:
10.00 Hz
Analog Output Scaling: 1 V = 0.2 Hz
This variable is the speed error obtained by subtracting the speed feedback from the speed reference. It is
useful for checking the step response of the speed loop.
Torque Reference [Torque reference]
Linear number:
291
Minimum value:
-1.500 pu
Maximum value:
1.500 pu
Analog Output Scaling: 5.0 V = 1.0 pu
This variable is the torque reference, which is the output of the speed regulator after the torque rate limit and
the motoring and generating torque limits have been applied. A value of 1.00 corresponds to rated torque. It is
positive for forward torque and negative for reverse torque.
Prior to Rev 4.60/5.00, this variable was scaled in per unit based on the motor rated kVA and was about 10%
lower.
Isq Command [Isq command]
Linear number:
292
Minimum value:
-2.000 pu
Maximum value:
2.000 pu
Analog Output Scaling: 5.0 V = 1.0 pu
This variable is the Q-axis stator current command obtained by dividing the torque reference by the flux
reference. It is positive for motoring and negative for generating.
Icq Command [Icq command]
Linear number:
293
Minimum value:
-1.000 pu
Maximum value:
1.000 pu
Analog Output Scaling: 5.0 V = 1.0 pu
This variable is the Q-axis capacitor current command. It is an estimate of the Q-axis current provided by the
motor filter capacitor.
Iy Command [Iy command]
Linear number:
294
Minimum value:
-2.000 pu
Maximum value:
2.000 pu
Analog Output Scaling: 5.0 V = 1.0 pu
This variable is the torque current command obtained by subtracting Icq Command from Isq Command.