Yaskawa Large Capacity Sigma II Series - Manual (Page 120)

4 Parameter Settings and Functions
4.2.8 Torque Feed-forward Function
4-44
External Speed Limit Function
This function uses V-REF (CN1-5) as external speed limit input and sets input voltage range
by Pn300. Set the range according to host computer and the output state of external circuit.
The factory setting is ±1% of the rated motor speed or 6 V.
„ Principle of Speed Control
Torque reversely proportional to the difference between the speed limit and the speed is fed back to
return the system to within the control speed range when the control speed range is exceeded. The
actual motor speed limit will thus be increased by negative loads.
4.2.8 Torque Feed-forward Function
The torque feed-forward function is used only in control mode except for torque control.
This function shortens positioning time, differentiates a speed reference at the host controller
to generate a torque feed-forward reference, and inputs this reference together with the
speed reference to the SERVOPACK. Too high a torque feed-forward value will result in
overshooting or undershooting. To prevent this, set the optimum value while observing sys-
tem response.
Connect a speed reference signal line to V-REF (CN1-5 and 6) and a torque feed-forward
reference signal line to T-REF (CN1-9 and 10).
Pn300 Speed Refer-
ence Input
Gain Unit:
0.01V/rated
speed
Setting
Range:
150 to 3000
Factory
Setting:
600
Speed/Torque
Control
INFO
Motor speed
V-REF
Speed limit range
-
V-REF
Position
reference
Kp Pn100 Current loop M
PG
Differ-
ential K FF
Speed
calculation
Integration
(Pn101)
+
+
+
+
+
T-REF
Servomotor
Encoder
Host controller SGDH SERVOPACK
Kp: Position loop gain
K
FF
: Feed-forward gain
+ +
Pn400
Pn300
-
Divider