Siemens SINAMICS Series Operating Instructions Manual page 571

Remark: The functions shown in function diagram 6810 have the following execution
sequence:
● Generation of the speed setpoint (r52174)
● Selection of the actual speed value (r52167)
● PT1 element (r52179)
● Bandstop filter 1 (r52177)
● Bandstop filter 2 (r52178)
● DT1 element (r52169)
● Lead/lag element (r52156)
● Generation of the setpoint/actual-value difference (r52165)
Reference model
The reference model represents the P-controlled speed control loop and creates an
appropriately processed speed setpoint for the I-component. This means that the
I-component largely plays no role for setpoint changes, with the consequent improved,
overshoot-free response.
The reference model contains a PT2 element and a dead time element to emulate the
controlled system. See function charts 6810 and 6815.
Further, it is possible to feed in an external reference model (e.g. generated using DDC
function diagrams).
The reference model is set using the following parameters:
p50237 natural frequency
p50238 damping
p50239 deadtime
p50240 activation
The reference model is correctly set when the characteristics of the reference model output
(r52154) and the actual speed value (r52167) are virtually identical when the I-component of
the speed controller (p50224 = 0) is disabled.
SINAMICS DCM DC Converter
Operating Instructions, 12/2018, A5E34763375A
Descriptions of functions
10.14 Speed controller
569