Siemens SINAMICS S120 Function Manual page 599

Important notes for parameterization
The function is activated using p3700.2 = 1.
The function uses information about the moment of inertia of the motor and axis, which is
parameterized outside the APC function module. Parameter p0341 (motor moment of
inertia), p0342 (scaling, motor moment of inertia) and p1498 (load moment of inertia) are
used. The formula for the overall moment of inertia is (p0341 · p0342 + p1498).
These parameters should be correctly parameterized before optimizing the function. The
values are incorporated in the control loop gain! This means that if the value is subsequently
changed, this can impact the control - and in the worst-case scenario, can even result in
control instability.
The first optimization of the function can be very quickly and simply performed using
parameter p3752. The axis oscillation frequency is parameterized. If this value is changed,
then automatically parameters p3709 (PT1 lowpass), p3751 (highpass) and p3761
(controller gain) are overwritten with a preassignment, depending on this frequency. The
moments of inertia are incorporated in the calculation (see the section above). It is important
that these values are correctly preassigned for the calculation.
It makes sense to use a PT1 lowpass filter (p3709). We recommend a time constant that is
approximately 1/10 of the oscillation frequency in Hz.
The highpass filter is active (p3751). It can make sense to use this, especially if in the
process, the axis is subject to static or low-frequency forces.
Two feedback branches via p3761 and via p3766 are active. However, generally it is
sufficient to just use the first branch (p3761). Frequently, practical values for the gain lie in a
range between 1 ms and 10 ms; however, this depends on the mechanical system of the
axis.
The APC filters are also effective, and when required can be used (see Chapter "Additional
Information (Page 619)").
For applications where a high contour precision is required (in the mold making area) we
recommend that p3700.3 is set = 1. As a consequence, the setpoint motion of the axis within
APC is better taken into account.
Measuring the function
The following measuring functions can be used to measure the "APC without sensor on the
load side" function:
● APC open circuit
● APC closed circuit (if a direct measuring system is being used)
● Speed controller reference frequency response
● Position controller reference frequency response
You can find detailed information on how to perform these measurements in Chapter
"Measuring frequency responses (Page 622)".
Drive functions
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
8.14 Advanced Position Control (including Active Vibration Suppression)
Function modules
599