Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive - Air-Cooled (A Frame) - Manual (Page 220)

4-66 Commissioning
7000A-RM001A-EN-P – January 2011 7000 “A” Frame
L Leakage High - indicates that the measured leakage inductance
is greater than 0.35 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.
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.
3. FluxSpeed Regulator [INDUCTION MOTORS]
Note: For synchronous motors, please refer FluxSpeed Regulator
for Synchronous motor.
This method combines the auto-tuning of the Flux and Speed
regulator in a single step. It calculates parameters, Lm Rated (P131),
T Rotor (P132) in Motor Model Group and Total Inertia (82) in
Speed Control group.
Note: During this auto-tune step the motor will run at speed set
in Autotune Spd Cmd. The default setting is 30Hz. Make
sure the motor rotates during this auto-tune. Motor rotation
must be verified either physically or monitoring FlxFbk
VoltModel (342). It is possible that stall condition may
calculate wrong tuning parameters. If it happens, make
sure the tuning parameters Lm Rated, T Rotor, Total
Inertia are set to default before starting this tuning again.
• Flux Regulator
The tuning of the flux regulator for an induction motor is determined
by three parameters:
1. FlxReg Bandwidth in Flux Control
2. Lm Rated 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. Lm Rated 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.
Tuning Procedure (cont.)