Siemens SINAMICS DCM Compact User Manual page 44

Switchover of the power unit topology - option S50
Selection of the required power unit topology and function
The required power unit topology can be selected on the parallel switching master with a
BICO input (see p51790) and is passed on internally to the parallel switching slaves. The
p51790 setting on the parallel switching slaves has no effect.
If the required power unit topology does not match the currently active topology, a switchover
is triggered. Switchovers that have been started are carried out in full, and only then is a
further switchover possible.
Control of the contactors for the power unit topology
The contactors are controlled via two BICO outputs (see r53312.0 and r53312.1) on the
parallel switching master, and these generate the selected power unit topology. The
corresponding BICO outputs on the parallel switching slaves must not be used.
The contactors can only be switched in a de-energized state.
During power up of the SINAMICS DCM, both power unit topologies are switched off. After
this, the two power unit topologies are mutually locked inside the device so that only one
power unit topology can be switched on. For safety reasons, the contactors must also be
mutually locked via auxiliary contacts as shown in function block diagram 9360.
Feedback from the active power unit topology
The active power unit topology is queried on the parallel switching master using a BICO
input (see p51791). The corresponding BICO input on the parallel switching slave has no
effect.
Switchover
The switchover of power unit topology is permitted in every operating state.
In the event of a switchover to the "Operation" state, current reduction, controller disable and
firing pulse inhibit are carried out and then the hardware is switched via the contactors. With
the feedback from the active power unit topology, the firing pulses and the controller are
released again.
During the controller disable and firing pulse inhibit, the SINAMICS DCM is in operating state
o1.8.
The duration of the current-free pause during the switchover is influenced primarily by the
duration of the hardware switchover by the contactors.
Two times can be set:
p51792
p51793
44
Stabilization time for the feedback from the current power unit topology
A change to the feedback signal is only effective if the signal features the new
state continuously for longer than the stabilization time.
During this time the previous state remains effective.
Maximum duration of switchover
Once this time has elapsed, the feedback from the active power unit topology
must match the one requested.
12-pulse applications
Compact User Manual, 09/2015, A5E34871844H