Parallel Connection Of Basic Line Modules - Siemens Sinamics S120 Function Manual

12-pulse infeed
For a 12-pulse infeed, the two redundant infeeds with the same power rating are supplied
from a line supply via a three-winding transformer. Depending on the transformer design, the
line-side voltages of the two infeeds will include minor tolerances of between about 0.5 % to
1 %. These can cause slightly asymmetrical current distribution in normal operation when
uncontrolled infeeds are used and current derating factors must be applied accordingly. If the
full output needs to be available when one infeed fails, then each infeed must be
dimensioned to carry the full current.
6-pulse, 12-pulse infeed
When separate Control Units are used, pre-charging may not be synchronized accurately
enough, i.e. a converter system must be able to pre-charge the total capacity of the drive
line-up. Pre-charging power for the DC link in parallel operation must be dimensioned so that
the capacitance of the DC link can be fully charged by a single converter system. Otherwise
a separate pre-charging device must be provided.
Configuring a parallel connection
Additional information on configuring parallel power units connections can be found in the
"SINAMICS Low Voltage Configuration Manual".
7.11.1.1

Parallel connection of Basic Line Modules

Features of Basic Line Modules:
● The DC link voltage is greater than the rms value of the line rated voltage by a factor of
● They are used in cases where regenerative feedback capability is not required.
● If regenerative operating states occur in the drive line-up, Braking Modules that convert
Basic Line Modules are available for the following voltages and power ratings:
Table 7- 7
Line supply voltage
380 to 480 V AC, 3-phase
500 to 690 V AC, 3-phase
The following rules must be observed when connecting Basic Line Modules in parallel:
● Up to 4 identical Basic Line Modules can be connected in parallel.
● A common Control Unit must always be used to implement the parallel connection.
● Special Line Connection Modules are available for the parallel connection.
Drive functions
Function Manual, (FH1), 01/2012, 6SL3097-4AB00-0BP2
1.35.
the excess energy to heat in braking resistors must be used.
Basic Line Modules
7.11 Parallel connection of power units
Rated power
200 ... 710 kW
250 ... 1100 kW
Function modules
405