Rockwell Automation 1557 MEDIUM VOLTAGE AC DRIVE - Manual (Page 74)

6-18 PARAMETER AND VARIABLE DESCRIPTIONS
1557-UM050F-EN-P – June 2013
Magnetizing Inductance [L magnetizing]
Linear number:
131
Minimum value: 1.00 pu
Maximum value: 15.00 pu
Default value: 4.00 pu
This parameter specifies the per unit motor magnetizing inductance. Typical values of this parameter are in the
range 2.0 pu to 6.0 pu for induction motors and 1.0 pu to 2.0 pu for synchronous motors. Magnetizing
inductance can change significantly with changes in load and flux. This parameter can be set manually or by
autotuning.
Rotor Time Constant [T rotor]
Linear number:
132
Minimum value: 0.10 sec
Maximum value: 10.00 sec
Default value: 1.00 sec
This parameter specifies the rotor time constant of the motor. Typical values are in the range 1.0 to 2.0 sec.
The rotor time constant varies significantly with rotor temperature (due to the change in rotor resistance), which
has some effect on the response of the flux regulator and the calculation of the slip frequency for induction
motors. This parameter can be set manually or by autotuning.
Filter Capacitor [Filter capacitor]
Linear number:
133
Minimum value: 0.00 pu
Maximum value: 2.00 pu
Default value: 0.42 pu
This parameter specifies the per unit effective motor filter capacitance calculated from the capacitor nameplate
parameters and the voltage rating of the motor. It is not saved and is recalculated when any of the parameters
affecting its value are changed. The normal range for this parameter is 0.40 to 0.60 pu. A warning will be
displayed if this parameter is outside the range of 0.25 to 0.75 pu.
Magnetizing Inductance Measured [L magn measured]
Linear number:
134
Minimum value: 1.00 pu
Maximum value: 15.00 pu
Default value: N/A
This parameter represents the motor magnetizing inductance measured by the drive control. It is obtained by
dividing the measured flux feedback by the magnetizing current. This parameter is not saved and is
continuously recalculated.
Lmd [Lmd]
Linear number:
135
Minimum value: 0.00 pu
Maximum value: 10.00 pu
Default value: 1.00 pu
This parameter specifies the d-axis magnetizing inductance for synchronous motors. It can be set manually or
by autotuning. This parameter is not used for induction motors.
This parameter was added in Rev 5.10 and is not present in 4.xx.