External torque reference source, Figure 30 - torque reference path – Rockwell Automation 20G PowerFlex 750-Series AC Drives User Manual
Page 263
Rockwell Automation Publication 750-RM002B-EN-P - September 2013
263
Motor Control
Chapter 4
Figure 30 - Torque Reference Path
There are additional internal Torque Reference sources within the drive such as
from a variety of Position Regulator outputs for the motor to develop the
corresponding amount of torque necessary to follow a point to point position
profile, cam profile, maintain a set position or follow a Motion Planner directed
profile.
The torque reference can be trimmed by Friction Compensation, Inertia
Adaption, or Load Observer estimator as the application may dictate. Torque
Step, an amount of torque reference step change, can be injected to simulate a
load disturbance.
External Torque Reference Source
The Torque Reference can also be established via analog or communication
media as a Setpoint reference or brought into the drive externally from a variety
of sources including an independent controller or another drive (for load sharing
configurations).
When the PowerFlex drive is operated in Torque mode, an alternate source of
reference, generally an external signal, is directed to the Torque Control as an
active torque reference. Once the scaling is complete on both P675 [Trq Ref A
FOC
Perm Magn
& Vector
Control
Current
Processing
Motor
Load
E
1
E
2
Gear
( Spd Reg Out )
+
+
Torque
Ref
Selection
Speed/
Torque/
Position
Mode
Selection
675
Trq Ref A Sel
680
Trq Ref B Sel
PID Output Sel
1079
PID Torque
Trim / Excl
Selection
+
+
686
Torque Step
Notch
Filter
-
+
+
Inertia
Adaption
Load
Observer/
Estimator
Limit
690
Limited Trq Ref
Torque Control
Torque
Limit
Generation
685
Selected Trq Ref
Actv SpTqPs
Mode
313
1567
FrctnComp
Out
+
Friction Comp
1560
FrctnComp
Mode
640
Filtered
SpdFdbk
PI Regulator
Speed Control – Regulator
Lead/Lag
Filter
Lead/Lag
Filter
645
647
Speed Reg Kp
Speed Reg Ki
636
Speed Reg BW
131
Active Vel
Fdbk
Final Speed Ref
620
Droop RPM
at FLA
660
SReg Output
520
Max Fwd Speed
521
Max Rev Speed
640
Filtered
SpdFdbk
597
Limit
Torque Reference