Parameter and variable descriptions – Rockwell Automation 1557 MEDIUM VOLTAGE AC DRIVE User Manual
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PARAMETER AND VARIABLE DESCRIPTIONS
1557-UM050F-EN-P – June 2013
23 Motor Model Variables
Stator Frequency [Stator frequency]
Linear number:
337
Minimum value:
0.0 Hz
Maximum value:
100.0 Hz
Analog Output Scaling: 1.0 V = 12.8 Hz
This variable is the measured stator frequency of the motor. It is positive for both directions of rotation.
Isd [Isd]
Linear number:
338
Minimum value:
-2.000 pu
Maximum value:
2.000 pu
Analog Output Scaling: 5.0 V = 1.0 pu
This variable is the calculated D-axis or magnetizing component of the stator current. It is positive for
magnetizing and negative for demagnetizing.
Isq [Isq]
Linear number:
339
Minimum value:
-2.000 pu
Maximum value:
2.000 pu
Analog Output Scaling: 5.0 V = 1.0 pu
This variable is the calculated Q-axis or torque component of the stator current. It is positive for motoring and
negative for generating.
I Stator [I stator]
Linear number:
340
Minimum value:
0.000 pu
Maximum value:
2.000 pu
Analog Output Scaling: 5.0 V = 1.0 pu
This variable is the stator current magnitude.
Flux from Current [Flx from current]
Linear number:
341
Minimum value:
0.000 pu
Maximum value:
1.500 pu
Analog Output Scaling: 5.0 V = 1.0 pu
This variable is the calculated rotor flux magnitude derived from the measured current feedback and the motor
model parameters. It is not valid at stator frequencies below about 4 Hz unless the optional tachometer is
installed.
Flux from Voltage [Flx from voltage]
Linear number:
342
Minimum value:
0.000 pu
Maximum value:
1.500 pu
Analog Output Scaling: 5.0 V = 1.0 pu
This variable is the measured rotor flux magnitude as determined by the hardware flux reconstruction using the
stator voltage and current feedback. It is not valid at stator frequencies below approximately 4 Hz.
Slip Frequency [Slip frequency]
Linear number:
343
Minimum value:
-2.00 Hz
Maximum value:
2.00 Hz
Analog Output Scaling: 1.0 V = 3.2 Hz
This variable is the calculated slip frequency of the motor. It is positive for motoring and negative for
generating. For synchronous motors, this variable is always zero.