Siemens SINAMICS DCM Operating Instructions Manual page 394

Descriptions of functions
10.12 Adaptation of the armature and field current controller
Inductance at a very low current:
L(0) = p50111 (La) or p50116 (Lf)
Inductance at the rated motor current:
L(I_Mot) = p50111×p51591 (La×λ
Effect of the adaptation
The SINAMICS DCM converter provides the option of adapting the gain of the armature
current controller or the field current controller to the existing non-linearities:
Compensating gating unit non-linearities:
The controller gain is normally set so that in the range of the largest controlled system gain
(i.e. where the armature is in the discontinuous current range or for the field, with a firing
angle of 90°) the required control behavior is obtained. For other currents, the current
controller becomes appropriately slower. When the current controller adaptation is activated,
the current controller gain is increased inversely proportional to the controlled system gain.
As a consequence, the controller behavior is approximately the same at any current.
Compensating non-linear inductances:
The controller gain is normally set so that at a high current, the required control behavior is
obtained. At low currents, the current controller becomes appropriately slower. When the
current controller adaptation is activated, the current controller gain is increased
proportionally to the inductance. As a consequence, the controller behavior is approximately
the same at any current.
Activating the controller adaptation
The current controller adaptation is not activated in the factory setting.
Reason:
When the adaptation is set, this means that the control behavior must be precisely checked
at various currents. In many applications, the improved control behavior that can be thus
achieved isn't necessary anyway. This is why in these cases it doesn't make any sense to
"invest" this time when commissioning the system.
394
) or p50116×p51597 (Lf×λ
a
Operating Instructions, 06.2010, C98130-A7067-A1-02-7619
)
f
SINAMICS DCM Control Module