Parallel Connection Of S120 Smart Line Modules - Siemens SINAMICS G130 Engineering Manual

Fundamental Principles and System Description
Engineering Information

Parallel connection of S120 Smart Line Modules

Parallel connections of Smart Line Modules 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 °.
6-pulse parallel connection of S120 Smart Line Modules
With the 6-pulse parallel connection, up to four Smart Line Modules are supplied by a common two-winding
transformer on the line side and controlled by a common Control Unit.
6-pulse parallel connection of S120 Smart Line Modules
As Smart Line Modules have no electronic current sharing control, the current must be balanced by the following
measures:
•
Use of line reactors with a relative short-circuit voltage of u
•
Use of symmetrical power cabling between the transformer and the Smart Line Modules (cables of
identical type with the same cross-section and length)
The current reduction from the rated value for individual Smart Line Modules in a parallel connection is 7.5 %.
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