12-pulse parallel connection
3.1 Topologies
12-pulse applications
12 Compact User Manual, 09/2015, A5E34871844H
Figure 3-2 12-pulse parallel connection (2), block diagram
For the converter topologies as shown in Fig. 3-1 and Fig. 3-2, the following mixed operation
is permissible:
Master side: 4Q unit(s)
Slave side: 2Q unit(s)
This means, in torque direction 1, 12-pulse operation – and in torque direction 2, 6-pulse
operation.
In some special cases, this operating mode is used to address the following requirements:
● Asymmetrical current demand (infeed power is far higher than the regenerative infeed
power)
● A high-speed DC breaker should be used in the armature circuit for fast shutdown in
regenerative operation. This high-speed breaker only has to be dimensioned for
regenerative operation (energy recovery) – and is only necessary for the 4Q units.
Reactor to decouple the partial converters: We recommend that individual reactors are used
instead of an interphase transformer.
Reason: In 6-pulse operation, current only flows through the interphase transformer at one