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

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- 9
Line supply voltage
380 to 480 V 3 phase AC
500 to 690 V 3-phase AC
The following rules must be observed when connecting Active Line Modules in parallel:
● Up to four identical Active Line Modules can be connected in parallel.
● Active Line Modules can only be connected and operated in parallel in the vector control
● A common Control Unit must always be used to implement the parallel connection.
● Special Line Connection Modules are available for connecting the modules in parallel.
● With multiple infeeds, power must be supplied to the systems from a common infeed
● A derating factor of 5% must be taken into consideration, regardless of the number of
The following measures help to ensure balanced currents in parallel connections of Active
Line Modules:
● Reactors in the Clean Power Filters of the Active Interface Modules.
● Use of symmetrical power cabling between the transformer and the parallel-connected
● The current reduction from the rated value for individual Active Interface Modules / Active
Drive functions
Function Manual, (FH1), 04/2014, 6SL3097-4AB00-0BP4
Active Line Modules
mode.
point (i.e. the modules cannot be operated on different line supplies).
modules connected in parallel.
Active Interface Modules / Active Line Modules (cables of identical type with the same
cross-section and length).
Line Modules in a parallel connection is 5%.
8.10 Parallel connection of power units
Rated power
132 ... 900 kW
560 ... 1400 kW
Function modules
527