Parallel Connection Of Active Line Modules - Siemens SINAMICS S120 Function Manual

6-pulse parallel connection of 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 synchronously controlled by a
common Control Unit.
As Smart Line Modules have no current compensation control, the current must be balanced
by the following measures:
● Use of suitable line reactors for the Smart Line Modules.
● Use of symmetrical power cabling between the transformer and the parallel-connected
Smart Line Modules (cables of identical type with the same cross-section and length).
● The current reduction (derating) from the rated value for individual Smart Line Modules in
a parallel connection is 7.5%.
12-pulse parallel connection of Smart Line Modules
For 12-pulse parallel connections, up to four Smart Line Modules are supplied by a three-
winding transformer on the line side. In this case, an even number of modules, i.e. two or
four, must be divided between the two secondary windings. In contrast to Basic Line
Modules, the Smart Line Modules of both subsystems have to be controlled by two Control
Units due to the 30° phase displacement in the input voltages.
8.10.1.3

Parallel connection of Active Line Modules

Active Line Modules can supply motoring energy and return regenerative energy to the line
supply.
The parallel connection of up to four Active Line Modules is supplied by a shared two-
winding transformer and controlled synchronously by a shared Control Unit. The modules
must not be connected to the supply via a three-winding transformer with phase-displaced
secondary voltages.
Active Line Modules produce a stabilized DC voltage that remains constant regardless of
fluctuations in the line voltage (the line voltage must range within the permissible tolerances).
The DC-link voltage is greater than the rms value of the line rated voltage by a factor of 1.5.
Active Line Modules draw a virtually sinusoidal current from the supply system and cause
virtually no line harmonic distortions.
Active Line Modules in chassis format are available for the following voltages and power
ratings:
Table 8- 11
Line supply voltage
380 to 480 V 3 phase AC
500 to 690 V 3-phase AC
Drive functions
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Active Line Modules
8.10 Parallel connection of power units
Rated power
132 ... 900 kW
560 ... 1400 kW
Function modules
567