Drive Configuration
Controller Tuning
1. Set Kr = 1 and Tn = 0, and activate the
Bode
plot view.
2. With the cross-hair search the frequency
f
gc
where
H
o
(f
gc
)
has a phase margin of 60° (Figure 46,
marker d)).
3.
Read the amplitude
A
gc
at frequency
f
gc
in
dB.
4. An initial value for the gain and the time constant can now be calculated with the following equa-
tions (see also Figure 48):
Kr
=
10
−
A
gc
20
Tn
=
10
2
π
f
gc
5. Use the criteria above to further optimize the current controller.
6. Press the
Commit
button to activate the parameter changes on the drive.
5.4.3 Position Controller Structure
Figure 49 shows the controller structure of the position controller. It consists of a PIDT1-controller with
proportional gain
Kp,
integral gain
Ki
and derivative gain
Kd
. The bandwidth of the derivative term can
be restricted with the low pass time constant
T1
. With the
IntegratorOutputLimit
wind-up of the inte-
gral can be avoided. Additionally five filters of second order can be configured.
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Figure 48: Tuning of the current controller. The figure to the left shows the bode plot with Kr = 1 and Tn=0. A phase
margin of 60° (angle = -120°) is reached at 2188Hz with a magnitude of -28.6dB. Based on the rule of thumb this
would result in Kr = 27 and Tn = 0.0007. The figure to the right shows the further optimized transfer function with
Kr=23 and Tn=0.0001.
