Automatic Pre-Assignment And Adaptation During Operation - Siemens SINAMICS S120 Function Manual

Additional settings and displays
● Set the dynamic response factor (p5272) for the entire P gain of the speed controller.
● Set the estimated load moment of inertia component for the P gain of the speed controller
with the load dynamic response factor (p5273).
● Display the estimated dynamic response (r5274) of the speed control loop as PT1 time
constant.
● Set the same time constants for the dynamic response time constant (p5275) so that the
interpolating drives receive a defined dynamic response via the precontrol. However, this
does not always ensure positioning without overshoot.
● The estimated Kv factor is displayed (r5276). This value can be used for a higher-level
control system, to set the position controller gain. Precondition: DSC is active in the drive.
● The estimated precontrol symmetrizing time is displayed (r5277). This value can be used
for a higher-level control system, to symmetrize the position controller precontrol.
Precondition: DSC is active in the drive.
4.8.2.2

Automatic pre-assignment and adaptation during operation

Automatic pre-assignment
When the "Online tuning" function is activated, settings are made that ensure the safe
operation of the online tuning.
Current setpoint filter
The natural frequency of the first PT2 filter behaves proportional to the current controller and
speed controller cycles. The faster the sampling, the higher the positive feedback frequency
and therefore the higher the frequency must be set for the current setpoint filter.
A lower dynamic response via p5272 makes the control loop less sensitive to resonance
from the drive train.
A higher dynamic response via p5272 makes the control loop more sensitive to resonance
from the drive train.
The instability of the control loop through resonance can also be avoided through the
parameterization of additional bandstop filters in the current setpoint.
Actual speed value filter
An actual speed value filter is required, for example, when the resolution of the encoder is
relatively poor. Depending on the encoder resolution and the motor moment of inertia, an
actual speed value filter (p1441) is calculated. The time constant of the actual speed value
filter is taken into account in the calculation of the controller parameters.
Adaptive resonance filter
The limit frequencies for the adaptive resonance filter are pre-assigned according to the set
sampling time. These can be changed manually.
Drive functions
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Servo control
4.8 Autotuning
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