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

Page 242

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242

Rockwell Automation Publication 7000L-UM301D-EN-P - June 2014

Chapter 4

Commissioning

8.

Adjust the scope to trigger on the rising edge of the dc current reference
and observe the dc current feedback on the other channel. The step
response will probably have noticeable overshoot, indicating that the dc
link time constant is set too low.

9.

Adjust parameter

T DC Link until the current feedback rises to about 63%

of its final value in 10 ms as shown in

Figure 210

. The overshoot should

now be quite small. Increasing

T DC Link causes the rise time to increase.

Since the desired step response is slightly under-damped,

T DC Link

should not be increased beyond the value at which the overshoot
disappears.

Figure 209 - Current Regulator Tuned Incorrectly

Figure 210 - Current Regulator Tuned Correctly

10.

Set parameter

CurReg Bandwidth to the normal value of 200 rad/sec.

Confirm that the rise time of the current feedback is now approximately 5
ms and that the overshoot is not excessive.

11.

Set parameter

Idc Ref Step to zero. The dc link current will return to a

steady level given by

Idc Test Command.

12.

Stop the drive. Set parameters

Operating Mode to Normal, and Idc Test

Command to 0.000pu.

Idc Reference

Idc Feedback

63%

0%

Idc Reference

Idc Feedback

63%

0%