Siemens SINAMICS DCM Manual page 532

10.14 Adaptation of the armature and field current controller
The current controller (armature current controller and field current controller) of the
SINAMICS DCM operate with a controlled system that is very non-linear.
Types of non-linearity
There are 2 types of non-linearity:
1. Non-linearity of the gating unit:
In the armature circuit, there is a significant difference in the controlled system gain (= line-
commutated thyristor converter in the B6 bridge connection) between discontinuous and
continuous current.
In the field circuit, the system is essentially always in the discontinuous current range, but
the control characteristic of the B2Z or B2 bridge manifests a significant degree of non-
linearity.
SINAMICS DCM DC Converter
Operating Instructions, 02.2015, A5E34763375/RS-AA/001
10.14 Adaptation of the armature and field current controller
ac.maher.co.ir
Descriptions of functions
533