Siemens SINAMICS S120 Function Manual page 114

Servo control
5.9 Autotuning
Measuring via noise excitation
The test signals comprise, on the one hand, a noise excitation during which the drive executes
a motion with a superimposed noise signal for a few seconds. The following settings are
required for this:
● The speed controller gain is set with p5301.0 = 1.
Parameter p5292 is a multiplier for this gain. An amplitude reserve of 7 dB and 45° phase
margin is taken into account with p5292 = 100%.
● Current setpoint filters 2 to 4 are parameterized with p5301.1 = 1.
These filters are set in order to achieve greater gains in the speed control loop. Typically,
band-stop filters are applied to mechanical resonances. Filters are only set when a greater
speed controller gain p1460 can be achieved.
● Active oscillation damping is parameterized by setting p5301.5 to 1.
The frequency of the load oscillation detected is set in p3752 "Advanced positioning control
closed-loop controller pre-assignment for natural frequency of vibration". A requirement for
this is the function module "Advanced Positioning Control" (r0108.7 = 1) and p3700.2 = 1.
The load moment of inertia must also be determined using p5301.2 - or first manually
entered in p1498. Following this, Advanced Positioning Control must be activated by setting
p3700.0 to 1. An existing load oscillation can be dampened during the positioning action
using the oscillation damping control. The response to interference and synchronous
operation properties can be negatively impacted as a result of oscillation damping without
sensor on the load side.
Measuring via low-frequency speed setpoint signal
On the other hand, a very low frequency speed setpoint signal (triangular) is applied to the
drive. The motor makes a clearly visible movement. Distance amplitude and duration must be
set with parameters p5308 and p5309.
In this way, the moment of inertia of the drive train is estimated. All the remaining controller
parameters are set. The setting is performed in the same way as for "Online tuning".
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Function Manual, 06/2019, 6SL3097-5AB00-0BP2
Drive functions