Siemens SINAMICS S120 Function Manual page 127

Figure 4-5
The optimum speed controller setting can be determined via the automatic speed controller
optimization function (p1900 = 1, rotating measurement).
If the inertia load has been specified, the speed controller (Kp, Tn) can be calculated by
means of automatic parameterization (p0340 = 4). The controller parameters are defined in
accordance with the symmetrical optimum as follows:
Tn = 4 * Ts
Kp = 0.5 * r0345 / Ts = 2 * r0345 / Tn
Ts = total of the short delay times (contains p1442 and p1452)
If vibrations occur with these settings, the speed controller gain Kp must be reduced
manually. Actual-speed-value smoothing can also be increased (standard procedure for
gearless or high-frequency torsion vibrations) and the controller calculation performed again
because this value is also used to calculate Kp and Tn.
The following relationships apply for optimization:
● If Kp is increased, the controller becomes faster, although overshoot is reduced. Signal
● If Tn is decreased, the controller still becomes faster, although overshoot is increased.
When speed control is set manually, it is easiest to define the possible dynamic response via
Kp (and actual speed value smoothing) first before reducing the integral time as much as
possible. When doing so, closed-loop control must also remain stable in the field-weakening
range.
Drive functions
Function Manual, (FH1), 10/2008, 6SL3097-2AB00-0BP5
Speed controller
ripples and vibrations in the speed control loop, however, increase.
Vector control
4.3 Speed controller
127