Siemens SINAMICS S120, Руководство по эксплуатации функций

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Vector control
5.4 Speed controller
Drive functions
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
221
If the moment of inertia has been specified, the speed controller (K
p
, T
n
) can be calculated by
means of automatic parameterization (p0340 = 4). The controller parameters are defined in
accordance with the symmetrical optimum as follows:
T
n
= 4 · T
s
K
p
= 0.5 · r0345 / T
s
= 2 · r0345 / T
n
T
s
= total of the short delay times (contains p1442 and p1452)
If vibration develops with these settings, reduce speed controller gain K
p
manually. Actual
speed smoothing can also be increased (standard procedure for gearless or high-frequency
torsional vibration) and the controller calculation performed again because this value is also
used to calculate K
p
and T
n
.
The following relationships apply for tuning:
● If K
p
is increased, the controller becomes faster and overshoot is decreased. However,
signal ripples and oscillations in the speed control loop will increase.
● If T
n
is reduced, the controller also becomes faster. However, this increases the
overshoot.
When setting the speed control manually, you are advised to define the possible dynamic
response via K
p
(and actual speed value smoothing) first, so that the integral time can
subsequently be reduced as much as possible. Please note that the closed-loop control must
also remain stable in the field-weakening range.
To suppress any vibrations that occur in the speed controller, it is usually only necessary to
increase the smoothing time in p1452 for operation with an encoder or p1442 for operation
without an encoder or reduce the controller gain.
The integral output of the speed controller can be monitored via r1482 and the limited
controller output via r1508 (torque setpoint).
Note
In comparison with speed control with an encoder, the dynamic response of drives without
an encoder is significantly reduced. The actual speed is derived by means of a model
calculation from the converter output variables for current and voltage that have a
corresponding interference level. To this end, the actual speed must be adjusted by means
of filter algorithms in the software.