Rockwell Automation 20D PowerFlex 700S AC Drives with Phase II Control Reference Manual - Manual (Page 95)

Rockwell Automation Publication PFLEX-RM003E-EN-E - January 2011 95
Detailed Drive Operation Chapter 1
Parameter 776 [XReg Spd HiLim] sets the positive speed limit at which the
position regulator will output. The default is set to +10% of the base motor
speed.
In position follower, the position loop only needs to trim the speed a small
amount because the drive is setup to follow the master speed reference. Therefore,
[XReg Spd LoLim] and [XReg Spd HiLim] can be left at the defaults.
Tuning Tips
The speed regulator of the drive must be tuned prior to tuning the Position Loop.
Refer to
Speed PI Regulator on page 152 of this manual for tips on tuning the
speed regulator.
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 value for parameter 768 [PositReg P Gain] for increased
stability.
Parameter 770 [PositReg Integ] is the integral gain for the position loop.
[PositReg Integ] can be used but is disabled by default and is normally not
needed for position follower applications. To enable [PositReg Integ], set
parameter 740 [Position Control], bit 2 “Integ En” = 1. When [PositReg Integ] is
used, parameter 772 [XReg Integ LoLim] and parameter 773 [XReg Integ
HiLim] should be set with narrow limits (approximately -10% and 10% of base
motor speed).
Jogging a Position Follower Independent from the Master
The jog can be performed while the position loop is enabled and while the
position loop output is turned on.
BW] Reg [Speed
Gain] Filt [Strim2
BW] Filt [SpdTrim2
=