Siemens SINAMICS G130 Engineering Manual page 206

SINAMICS G150
Engineering Information
b) 6-pulse operation of G150 parallel converters with production date from autumn 2007
At 6-pulse operation, both rectifiers are connected to the same secondary winding of a two-winding transformer or to
a common infeed point, as illustrated in the following diagram.
6-pulse operation of SINAMICS G150 parallel converters with production date from autumn 2007
With the gating impuls generator for the thyristors implemented in the rectifiers of SINAMICS G150 parallel
converters supplied from autumn 2007, it is no longer necessary to separate the DC links of both partial converters
when operating in 6-pulse configuration. Thus it is no longer required to use motors with two electrically isolated
winding systems at the output side. The standard configuration for 6-pulse operation with SINAMICS G150 parallel
converters being produced from autumn 2007 is therefore:
•
The DC links of both partial converters are connected to each other.
•
It is possible to connect both, motors with two electrically isolated winding systems and motors with one
common winding system.
Note: The difference between the versions described for the time frames "up to autumn 2007" and "from
autumn 2007" simply lies in the improved version of the TDB board. The firmware version of the
converters does not have any significance within this context.
As the line-side rectifiers have no electronic current sharing control, the line-side currents must be balanced by the
following measures:
•
Use of line reactors with a relative short-circuit voltage of uk = 2 %. The omission of the line
reactors by chosing option L22 is not permissible.
•
Use of symmetrical power cabling between the line connection point and the parallel-connected
rectifiers (cables of identical type with the same cross-section and length)
The motor-side limitations and restrictions are described on the following pages in the section "Operation at motors
with two electrically isolated winding systems and one common winding system".
SINAMICS Engineering Manual – May 2008
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