Optimizing The Speed Controller - Siemens SINAMICS DCM Operating Instructions Manual

Commissioning
8.8 Manual optimization
 Checking the step response
8.8.3

Optimizing the speed controller

Basic information
The objective of the closed-loop control is to compensate the system deviation as a result of
changes to the setpoint and disturbances.
The evaluation is performed in the time domain:
● The control loop fulfills the requirement for steady-state accuracy, if the system deviation
● The overshoot defines the damping. For a step change of the setpoint or disturbance
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Procedure
- Set the function generator to a squarewave, with
step height = e.g. 5 %
offset = various values, e.g. 80 %
period = 1000 ms
pulse width = 500 ms
- Supply point: p50611[0] (see function diagram 6905)
- Set p50082 = 3 (field continuously on)
- Record signals r52268 (If-set) and r52265 (If-act)
- Change controller parameters Kp (p50255) and Tn (p50256) until the step
response provides a satisfactory result.
- The field current controller adaptation can be activated (see function chart 6908)
to eliminate the influence of non-linearity of the field inductance and gating unit.
as a result of a setpoint step (reference input) converges towards zero. The rise time t
and settling time t specify the speed.
aus
variable, the controlled variable must not excessively overshoot the steady-state final
value.
Figure 8-41 Setpoint step to evaluate a controller
Operating Instructions, 1.2012, C98130-A7066-A1-05-7619
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SINAMICS DCM DC Converter