Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) - Classic Control - Manual (Page 237)

4-78 Commissioning
7000-UM150I-EN-P – June 2013 7000 “B” Frame
2. Because of the design of the motor, this method of measuring
leakage inductance does not produce a valid result. The
leakage inductance will have to be obtained from the motor
data sheet, or if this is not possible, parameter "L total leakage"
should be set to its default value of 0.20 pu.
L leakage hi - indicates that the measured leakage inductance is
greater than 0.30 pu. Possible causes are:
1. The inductance of long motor cables is increasing the
apparent leakage inductance of the motor. In this case, the
measured leakage inductance is probably correct and
parameter "L total leakage" should manually be set equal to
"Autotune Ls".
2. The motor is very small (leakage inductance generally
increases with decreasing motor size).
3 Because of the design of the motor, this method of
measuring leakage inductance does not produce a valid
result. The leakage inductance will have to be obtained from
the motor data sheet. If this is not possible, parameter “L
total leakage should be set to its default value of 0.20 pu.
5. Flux Regulator
Induction Motor Flux Regulator
The tuning of the flux regulator for an induction motor is determined
by three parameters:
1. Flxreg bandwidth in "Flux Control"
2. L magnetizing in "Motor Model"
3. T rotor in "Motor Model"
"Flxreg bandwidth" should be set to the default value of 10 r/s for
almost all applications. "L magnetizing" and "T rotor" are usually
unknown and must be measured. Both of these motor parameters
change substantially with different operating conditions, but the
variations do not significantly affect the operation of the flux regulator.
The other aspect of flux control is the variation of motor flux with
speed. This is determined by two parameters:
1. Base speed in "Flux Control"
2. Flux command base speed in "Flux Command"