ABB ACSM1 Firmware Manual page 50

50
The figure below shows speed responses at a speed reference step (typically
1...20%).
n
%
n
N
A: Undercompensated
B: Normally tuned (autotuning)
C: Normally tuned (manually). Better dynamic performance than with B
D: Overcompensated speed controller
The figure below is a simplified block diagram of the speed controller. The controller
output is the reference for the torque controller.
reference
For more information on the use of the autotune function, see the description of
parameter
Drive control and features
A
B
Speed
+ Error
-
value
Actual speed
28.16 PI TUNE
C
Derivative
acceleration
compensation
Proportional,
integral
Derivative
MODE.
D
t
+
Torque
+
reference
+