Siemens SINAMICS S120 Function Manual page 526

Function modules
9.10 Parallel connection of power units
The parallel connection of a maximum of 4 identical ALMs of the Chassis format or a maximum
of 6 identical ALMs of the Chassis-2 format is supplied by a shared two-winding transformer
and controlled synchronously by a shared Control Unit. In the case of a parallel connection of
more than 4 power units, a stand-alone CU must be provided that is not used to operate any
additional drive objects (DOs). The modules must not be connected to the supply using a three-
winding transformer with phase-displaced secondary voltages.
Active Line Modules generate a regulated DC voltage that is kept consistent regardless of
fluctuations in the line voltage (the line voltage must range within the permissible tolerances).
Active Line Modules draw an almost sinusoidal current from the supply system and therefore
cause virtually no line harmonic distortions.
Active Line Modules are available for the following voltages and power ratings:
Line voltage
380 to 480 V 3 AC
500 to 690 V 3 AC
Features
Connecting Active Line Modules in parallel is characterized by the following features:
● The DC-link voltage is greater than the rms value of the line rated voltage by a factor of 1.5.
Active Line Modules (Chassis and Chassis-2 format)
The following preconditions and rules must be carefully observed when connecting Active Line
Modules in the Chassis format and Chassis-2 formats in parallel.
Requirements
The following power unit-specific preconditions apply when connecting Active Line Modules in
the Chassis and Chassis-2 formats in parallel:
● Chassis or Chassis-2 format
● For commissioning the parallel connection of ALMs of the Chassis format, a firmware
version of ≥ V4.0 must be available.
● When commissioning ALMs, Chassis-2 format connected in parallel, a firmware version of
≥ V5.2 must be available.
Rules
The following rules must be observed when connecting Active Line Modules (ALM) of the
Chassis format and Chassis-2 format in parallel:
● Up to 4 identical ALMs of the Chassis format or 6 identical ALMs of the Chassis-2 format can
be switched in parallel.
● A common Control Unit (CU) must always be used to implement the parallel connection.
● For the parallel connection of ALMs of the Chassis-2 format with more than 4 modules, the
DRIVE-CLiQ line must be separated. Up to 3 ALMs can be operated on one DRIVE-CLiQ
line. Additional ALMs must be connected to a separate DRIVE-CLiQ line.
● Special Line Connection Modules are available for the parallel connection.
524
Rated power
132 to 900 kW
560 to 1400 kW
Function Manual, 06/2019, 6SL3097-5AB00-0BP2
Drive functions