Rockwell Automation 20D PowerFlex 700S AC Drives with Phase II Control Reference Manual - Manual (Page 100)

100 Rockwell Automation Publication PFLEX-RM003E-EN-E - January 2011
Chapter 1 Detailed Drive Operation
Typically parameter 768 [PositReg P Gain] should be set between 1/5th to 1/3rd
of parameter 90 [Spd Reg BW].
Parameter 768 [PositReg P Gain] may be set higher using lead compensation on
the Position Regulator output. Lead-Lag filtering of the position regulator output
is accomplished via the Speed Trim 2 filter. Set parameter 25 [STrim2 Filt Gain]
and parameter 26 [SpdTrim2 Filt BW] so that:
For example, with parameter 90 [Spd Reg BW] = 40 radians/second, set
parameter 26 [SpdTrim2 Filt BW] = 200 radians/second and set parameter 25
[STrim2 Filt Gain] = 5. The lead-lag filter will effectively cancel the 1/40 sec lag.
This will allow a higher parameter 768 [PositReg P Gain] for increased stability.
Parameter 761 [Pt-Pt Filt BW] sets the bandwidth of a low pass filter which
affects smoothness at the start of deceleration in point to point mode. A high
filter bandwidth will produce a more square deceleration torque, one with a
higher level of jerk. Typical values are 5…100 (radians/second). A zero value will
bypass the filter. Too high of a value in [Pt-Pt Filt BW] will cause unstable
operation at the end of the move. The default = 25 radians/second.
Jogging
The jog can be performed while the position loop output is enabled and while the
position loop output is turned on.
Point to Point Re-Reference
Parameter 740 [Position Control], bit 10 “Pt-Pt ReRef ” allows the user to
perform a position re-reference when active. When this bit is set, the position
reference in parameter 758 [Pt-Pt Posit Ref ] can be changed to the position value
desired for the current location. This can be used as a home setup by moving the
load to the home position and then performing a position re-reference.
Example:
Set parameter 740 [Position Control], bit 10 “Pt-Pt ReRef ” = 1. Then set
parameter 758 [Pt-Pt Posit Ref ] = 0. If [Pt-Pt Posit Ref ] is set to a different
number, that will become the new position value. After setting parameter 758
[Pt-Pt Posit Ref ] to the desired value, set parameter 740 [Position Control], bit
10 “Pt-Pt ReRef ” = 0.
[SpdTrim2 Filt BW]
[STrim2 Filt Gain]
------------------------------------------------- [Spd Reg BW] =