36
Speed controller tuning
During the motor identification, the drive speed controller is automatically tuned. It is,
however, possible to manually adjust the controller gain, integration time and
derivation time, or let the drive perform a separate speed controller Autotune Run. In
Autotune Run, the speed controller is tuned based on the load and inertia of the
motor and the machine. The figure below shows speed responses at a speed
reference step (typically, 1 to 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.
Speed
reference
Calculated actual speed
Settings
Parameter groups
Diagnostics
Actual signal 01.02.
Program features
%
A
B
Error
+
-
value
23 SPEED CONTROL
C
D
Derivative
acceleration
compensation
Proportional,
integral
+
+
+
Derivative
and
20
LIMITS.
t
Torque
reference