Applications Of Parallel Connections - Siemens SINAMICS S120 Function Manual

Function modules
8.10 Parallel connection of power units
8.10.1

Applications of parallel connections

Power units can be connected in parallel (infeeds) in the following cases:
● 6-pulse circuit
The modules connected in parallel are supplied from a two-winding transformer.
● 12-pulse circuit
The modules connected in parallel are supplied via a three-winding transformer, whose
secondary windings 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 8-25
Note
Additional information on parallel power unit connections, particularly with regard to their
configuration, can be found in the "SINAMICS Low Voltage Configuration Manual
(http://www.automation.siemens.com/mcms/infocenter/dokumentencenter/ld/Documentsu20
Catalogs/lv-umrichter/sinamics-engineering-manual-lv-en.pdf)".
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.
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Parallel connection of power units - overview
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Drive functions