Standard Mode - Siemens SINAMICS Series Operating Instructions Manual

Descriptions of functions
10.28 Connecting units in parallel and in series
Extended topology
The topology of a 6-pulse parallel connection, comprising a master converter, one substitute
master, two slave converters, as well as an independent converter is shown in the following
diagram.
The converters SINAMICS DCM 1, DCM 2, DCM 3 and DCM 4 are operated in the n+m
operating mode. The SINAMICS DCM 5 converter is, regarding its power unit, independent
of the others. It only exchanges BICOs with them via the parallel interface.
Figure 10-76 6-pulse parallel connection, extended topology
Operating modes of the 6-pulse parallel connection
There are two operating modes:
● Standard mode
● n+m operation (also known as redundancy mode or redundant operation)

Standard mode

A SINAMICS DCM is defined as the master. This device carries out the closed-loop speed
control, the closed-loop armature-current control, the line synchronization tasks and
determines the firing points. The firing points and the thyristor pair to be fired are transferred
to the slave devices; all the slaves then fire the thyristor pairs at these points.
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SINAMICS DCM DC Converter
Operating Instructions, 12/2018, A5E34763375A