Rockwell Automation 7000L PowerFlex Medium Voltage AC Drive (C-Frame) - ForGe Control - Manual (Page 248)

248 Rockwell Automation Publication 7000L-UM301D-EN-P - June 2014
Chapter 4 Commissioning
Figure 211 - Speed Control Parameter Screen
2. Set parameter Total Inertia in Speed Control to an initial value of 1.0 sec if
it is a low inertial application (pumps etc). Set the parameter to 5.0
seconds if it is a high inertia application (e.g. ID Fans).
3. Assign parameter Speed Error in the Speed Control group to a test point e.g.
ITP1 on the DPM. This can be done similarly to the way that the meter
assignments were described earlier in the chapter. Then it can be displayed
on your oscilloscope.
4. Adjust the reference command to a value around the middle of the
operating speed range.
5. Start the drive and wait for it to accelerate to the commanded speed.
6. Set parameter Speed Ref Step in Speed Control to 0.8 Hz. The drive speed
will step up and down by this amount at regular intervals. The step of 0.8
Hz corresponds to 0.8V or 800mV on the test point. To capture the error
set the scope at 200mV/division and 200msec/division. Trigger the scope
on negative edge as shown in
Figure 212 .
7. Adjust the value of parameter Total Inertia until the speed rises to
approximately 63% of its final value in 1 second as shown in the figure. If
the response time is too fast, it indicates that
Total Inertia is set too high
and should be decreased. If the response is too slow, then Total Inertia is set
too low and should be increased.
Figure 212 - Correctly Tuned Speed Regulator
Speed Error
10 ms
63%
0%