Rockwell Automation 7000A PowerFlex Medium Voltage Drive (A-Frame) - Classic Control - Manual (Page 244)

4-70 Commissioning
7000A-UM150F-EN-P – June 2013 7000 “A” Frame
Parameter "Autotune Lc" in "Autotuning" group is set to the measured
value of commutation inductance, and parameter "Autotune select" is
set to Off. If the test is successful, parameter "L commutation" in
"Current Control" is set equal to "Autotune Lc". If the test fails, then
parameter "L commutation" is not changed and a warning is issued
indicating the cause of the failure:
L comm low - indicates that the measured commutation
inductance is less than 0.02 pu. The commutation inductance
must be tuned using the manual method described below.
L comm high - indicates that the measured commutation
inductance is greater than 0.15 pu. The commutation inductance
must be tuned using the manual method described below.
Commutation Inductance Manual Tuning (for 18P only)
1. Set parameter "Operating mode" in “Feature Select” to DC
Current to enter dc current test mode.
Current Control Parameter Screen
2. Set parameter "Idc command test" in “Current Control” to 0.400
pu.
3. Set parameter "L commutation" in “Current Control” to an initial
value of 0.05 pu.
4. Connect an oscilloscope to the test points labeled VAB1-OUT
and FAB1 on the SCBL board. Two sine waves of
approximately equal amplitude should be seen, with the
reconstructed line voltage FAB1 lagging the unfiltered voltage
VAB1-OUT by 90 degrees. Adjust the triggering and time base
to display the positive half cycle of VAB1-OUT with a scale of
20 degrees per major division.
5. Start the drive. The dc link current will rise to 0.4 pu.
Commutation notches will appear in the unfiltered line voltage
VAB1-OUT as shown in the figure. Some distortion will appear
in the reconstructed voltage FAB1 around the zero crossings.