Rockwell Automation 20G PowerFlex 750-Series AC Drives User Manual
Page 257
Rockwell Automation Publication 750-RM002B-EN-P - September 2013
257
Motor Control
Chapter 4
If the speed reference = 20 Hz and if the trim percentage = 25%, the resulting
trim is 20 Hz x 25% = 5 Hz, which when added to the speed reference = 25 Hz.
As the speed reference changes, the amount of trim also changes because it is a
percent of the speed reference. If the trim percentage = -25%, then the resulting
trim is 20 Hz x -25% = -5 Hz, the speed reference = 15 Hz.
Example 2
The following example shows the configuration and resultant of the fixed
amount trim function:
•
P545 [Spd Ref A Sel] = P546 [Spd Ref A Stpt]
•
P546 [Spd Ref A Stpt] = 20.00 Hz
•
P600 [Trim Ref A Sel] = P601 [Trim Ref A Stpt]
•
P601 [Trim Ref A Stpt] = 10.00 Hz
•
P2 [Commanded SpdRef ] = 30.00 Hz
If the speed reference = 20 Hz, and if the trim set point = 10 Hz, the speed
reference is 20 Hz + 10 Hz = 30 Hz. If the trim set point = -10 Hz, then the
speed reference = 10 Hz.
Example 3
The following example shows the configuration and resultant of utilizing both
the perfect and fixed amount trim function:
•
P545 [Spd Ref A Sel] = P546 [Spd Ref A Stpt]
•
P546 [Spd Ref A Stpt] = 20.00 Hz
•
P608 [TrmPct RefA Sel] = P609 [TrmPct RefA Stpt]
•
P609 [TrmPct RefA Stpt] = 25%
•
P600 [Trim Ref A Sel] = P601 [Trim Ref A Stpt]
•
P601 [Trim Ref A Stpt] = 10.00 Hz
•
P2 [Commanded SpdRef ] = 35.00 Hz
If the speed reference = 20 Hz, and if the trim percentage = 25%, that resulting
trim is 20 Hz x 25% = 5 Hz, and if the trim set point = 10 Hz, the speed reference
is 20 Hz + 5 Hz + 10 Hz = 35 Hz. If the trim percentage = -25% and the trim set
point = -10 Hz, then the speed reference = 5 Hz.