Adaptation Of The Controllers - Siemens SINAMICS DCM 6RA80 Faq

Structure diagram of the DC motor with elastically coupled flywheel and damping
K ; T
A A
u
m
A
M
-
-
With damping, m
F
With k of the gain of the damping element k
F
damping.
The characteristic values can be determined experimentally:
T : due to acceleration of the uncoupled motor at the current limit up to the rated speed of
M
the motor.
T + T : due to acceleration of the motor with a coupled flywheel.
M L
The natural frequency
the speed with an oscillograph while the couple drive is ramping up at the current limit.
So, you can see that this is a complex issue.
On the SINAMICS DCM, the frequency response of the controlled system is calculated with
p50051 = 29 as part of optimization of the drives with oscillating mechanical system and the
parameters p50225, p50226, and p50228 required for the speed control loop are
automatically set. We will therefore not look any further into this issue because the topic of
frequency characteristics has not been dealt with in this document.

Adaptation of the controllers

Speed controllers: The characteristic values of the speed controllers can be adapted
depending on an influencing variable (any connector variable), for example, to the actual
current value or the speed actual value, see Sheet 6805 in Chapter 2 of Parameter Manual..
For gear stage changing (change of the T
on main spindle drives, the Drive Data Set switchover (DDS0 to DDS3) can be used.
The current controller characteristics values can be adapted; each multiplied by one
connector variable. The change in firing angle required for a change in current of a certain
magnitude is different for discontinuous and continuous current. Thos non-linearity is
compensated for by the current controller precontrol.
In the case of field weakening operation, division by PHI is performed after the speed
controller (torque calculation can be selected). In this way, the speed controller output is the
torque setpoint to adapt the controlled system accordingly.
The relationship between the field current and the motor flux PHI is non-linear because of the
magnetization characteristic (non-linearity due to core saturation). The precontrol of the EMF
controller takes this into account depending in the magnetization characteristic of the motor
(recorded by field characteristic recording by means of p50051 = 27).
If the controlled variable reaches a limit, the integral-action component of the PI controller is
stopped so as not to integrate away too much which could only be triggered to integrated
K
T
T
M
-
n
M
= (n –n ) / (pT ) + k
M L F
of the flexible mechanical system can be calculated by recording
e
F
T
F L
n
m
F
* (n – n )
F M L
= d * 2 * N
F MN
depending on the gear stage) or C-axis operation
M
72
/ (60 * M ) and d as the
MN