Applications Of Parallel Connections - Siemens SINAMICS S120 Function Manual

7.11.2

Applications of parallel connections

Parallel connection of power units
Parallel connections of power units (infeeds can be implemented as either a 6-pulse circuit if
the parallel-connected modules are connected to a two-winding transformer, or as a 12-
pulse circuit if the parallel-connected modules are connected to a three-winding transformer
with secondary windings that supply voltages with a phase shift of 30 °). The following
diagram is an overview of the module variants discussed in this section for inclusion in power
unit parallel connections.
Figure 7-22 Parallel connection of power units - overview
Note
For further information about parallel connection of power units, especially instructions on
how to configure them, see "SINAMICS Configuration Manual for G130, G150, S120
Chassis, S120 Cabinet Modules, S150".
Infeed concepts - parallel (one CU) and redundant parallel (two CUs)
Some applications require redundant infeeds for a DC line-up. This requirement can be
fulfilled through the implementation of multiple, independent infeeds which are connected in
parallel to the DC-line-up. Depending on how the drive is dimensioned, the DC line-up can
continue operating at between 50 % to 100 % output when one infeed fails. With the
redundant variant of the infeed parallel connection, each infeed is controlled by a separate
Control Unit and is thus completely independent. With the non-redundant variant, a single
Control Unit generally controls all parallel-connected power units which then, from a practical
viewpoint, function like a single, high-output infeed.
The type of circuit required depends on whether the redundancy requirement applies only to
the infeed itself or also includes the supply-side transformers or the supply systems (see
"SINAMICS Configuration Manual G130, G150, S120 Chassis, S120 Cabinet Modules,
S150").
6-pulse infeed
With the 6-pulse infeed circuit variant, the two redundant infeeds of identical type are
connected to the supply system via a two-winding transformer. As both infeeds are supplied
Drive functions
Function Manual, (FH1), 10/2008, 6SL3097-2AB00-0BP5
Function modules
7.11 Parallel connection of power units
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