Rockwell Automation 21G PowerFlex 750-Series AC Drives Programming Manual - Manual (Page 125)

Rockwell Automation Publication 750-PM001J-EN-P - October 2014 125
Drive Port 0 Parameters Chapter 3
Fi
le
Grou
p
No. Display Name
Full Name
Description Values
Re
ad
-W
ri
te
Da
ta
T
ype
SPEED C
O
NTROL
Sp
ee
d C
om
p
665 Speed Comp Sel
Speed Compensation Select
Configures the Speed Compensation function, which is used in Vector Control modes to
create a feed forward compensation that is added into the speed reference. This helps
compensate for position tracking errors during acceleration. These tracking errors are
caused by the sample and hold process and delays caused by the position to velocity FIR
filter. Speed Compensation will help reduce position error in position follower
applications.
Available settings for this parameter are:
“Disabled” (0) – Function is disabled, speed compensation does not affect the speed
reference.
“Ramped Ref” (1) – Speed compensation function is enabled and uses an internally
generated ramped speed reference signal. The rate of change (derivative) of the speed
reference becomes the input to the Speed Compensation function. This is the most
common setting when speed compensation is in use.
“Rate Ref” (2) – Speed compensation function is enabled and uses an externally
generated speed rate signal. The rate of change or derivative of the speed reference is
supplied by P596 [Speed Rate Ref]. This signal is typically supplied by an external
controller when the speed reference ramp is generated external to the drive. Default:
Options: 0 = “Disabled”
0 = “Disabled”
1 = “Ramped Ref”
2 = “Rate Ref” RW 32-bit
Integer
666 Speed Comp Gain
Speed Compensation Gain
Adjusts the magnitude of P667 [Speed Comp Out]. This gain can be either manually set
or automatically determined as part of automatic gain mode for Vector speed control.
Automatic mode can be activated by selecting a motor speed feedback device in P125
[Pri Vel Fdbk Sel] and setting a non-zero speed regulator bandwidth in P636 [Speed Reg
BW]. In automatic mode, the gain is calculated internally using a table lookup from the
interrupt times and delays of the speed feedback FIR filter. For any other case – non-
vector control, open loop speed feedback, or zero bandwidth setting, the speed
compensation gain must be manually adjusted. Default:
Min/Max: –2.50
–/+32767.00 RW Real
667 Speed Comp Out
Speed Compensation Output
Displays the output of the Speed Compensation function. This value will be summed
with the speed reference, following the application of P555 [Spd Ref Scale]. Units:
Default:
Min/Max:
Hz
RPM
0.00
–/+P27 [Motor NP Hertz] x 8
–/+P28 [Motor NP RPM] x 8 RO Real