Siemens 6RA7086-6KS22 Operating Instructions Manual page 110

Connections
Basic operating principle of the "N+1 operation" mode:
In this mode it is possible to maintain operation with the remaining SIMOREG units if one unit
should fail (e.g. fuse blown in the power section, appearance of a fault message). The functional
SIMOREG units continue to run without interruption if one unit fails. During configuration, make
sure that the power of only n units (instead of n+1 units) is sufficient for the application.
The parameters described above cause one SIMOREG unit to be defined as the "standby master".
Providing the SIMOREG unit that is parameterized as the "master" functions correctly, the standby
master operates as a "slave". If the master fails, the standby master assumes the "master" function
(indicated by display parameter n810, segment 15 or binector B0225).
The "master" function is always transferred from the master to the standby master by sending a
telegram via an intact paralleling interface. The master still has sufficient time to transfer the
"master" function by sending a telegram even after its electronics supply voltage is switched off.
NOTE
An intact paralleling connection is essential for the redundancy mode of the armature supply. The
"master" function cannot be transferred if the paralleling cable is interrupted.
If the electronics supply for one unit fails, the complete drive must be shut down before it is
restored.
When the master is active, it sends the values set in accordance with U804.01 to 05. If a fault
occurs on the master (i.e. after the "master" function has been transferred to the standby master), it
sends the values set in accordance with U804.06 to 10.
When the standby master operates as a slave (i.e. when the master is active and functioning
correctly), it sends the values set in accordance with U804.01 to 05. When the standby master is
operating as the master (i.e. after the "master" function has been transferred owing to a fault on the
master), it sends the values set in accordance with U804.06 to 10.
For further details about the operating principle of SIMOREG units connected in parallel, see
Section 8, Function diagrams, Sheet G195 (Paralleling interface).
Notes:
• Control commands "Switch-on/Shutdown", "Enable operation", "Emergency stop" etc. must be
connected to a group of parallel-connected SIMOREG converters via the master device AND
the "standby" master device.
Terminals 37 and 38 must be permanently connected to terminal 34 on the slaves.
• The speed setpoint and the actual speed must be connected to a group of parallel-connected
SIMOREG converters via the master device AND the "standby" master device.
• All parameters except for those in the above list must be set identically on the master and the
standby master.
• Optimization runs must be started on the master device. All slaves must be connected and
ready to run when optimization is started.
The parameters described above enable the armature current to continue flowing without
interruption if a fuse blows in the armature or field power section (on any one power section), a
fault message appears on any one device or the electronics supply fails on any one device
(master, standby master or slave).
CAUTION
As soon as the paralleling connection is interrupted (either by unplugging the paralleling cable or
if the electronics supply voltage for the master fails), the master/slave assignment can no longer
be guaranteed to function correctly.
The electronics supply voltage for the standby master must be switched off before the
electronics supply voltage for the master is restored (in order to prevent two masters from being
simultaneously active).
6-24
Siemens AG
SIMOREG DC Master Operating Instructions
05.05
6RX1700-0AD76