12-pulse parallel connection
3.3 Commissioning
12-pulse applications
22 Compact User Manual, 09/2015, A5E34871844H
Specifying the operating mode
Two operating modes are supported:
Operation with firing angle interface (p51799 = 0 or p51799 = 21)
● Master (SINAMICS DCM 1): Closed-loop speed control, armature current closed-loop
control and field current closed-loop control
● Slave (SINAMICS DCM 2): Armature current closed-loop control
The master determines the theoretical firing angle and transfers it to its own gating unit and
to the gating unit of the slave. Both partial converters synchronize to their own network and
form their own firing points. However, both the master and the slave have their own current
controller which intervenes to make any corrections.
Operation with current setpoint interface (p51799 = 22)
● Master (SINAMICS DCM 1): Closed-loop speed control, armature current closed-loop
control and field current closed-loop control
● Slave (SINAMICS DCM 2): Armature current closed-loop control
The master determines the armature current setpoint and transfers this to its own armature
current controller and to the armature current controller of the slave. Both partial converters
control their own partial current independently.
For a 12-pulse parallel connection, restricted redundant operation is possible. With the
setting p51803 = 1, if a slave fails (devices with setting p51800 = 23 or 24) then, depending
on the minimum number of power units (set in p51802), this is tolerated. Master devices (12
pulse - master p51800 = 21, or 12 pulse slave - p51800 = 22) must remain operational. The
drive is shut down if one of the two fails. It is not possible to transfer the master – and
redundancy of armature and field (setting, p51803 = 2) is not possible. If the electronic
supply fails, or devices are removed with active bus terminating resistor, then for the device
in front, the bus terminating resistor should be activated using p51801 = 1. When reinstalling
the previously removed device, the change must be appropriately undone (p51801 = 0).