Redundancy Mode Of The Field Supply - Siemens 6RA7086-6KS22 Operating Instructions Manual

05.05
6.3.2.3

Redundancy mode of the field supply

In "N+1 operation" mode, a redundancy mode can also be defined for the field supply included in
the SIMOREG unit. The 3C, 3D output of the SIMOREG field supply for the master and the
standby master is connected in parallel with the motor field winding for this purpose.
In normal operation the field voltage is supplied via the master and the field firing pulses of the
standby master are disabled. If the master fails, it transfers the "master" function to the standby
master. At the same time, the field firing pulses of the master are disabled and the field voltage is
supplied via the standby master.
Since the field voltages are connected in parallel, part of the total motor field current flows via the
free-running branch of the relevant field power section with the disabled field firing pulses. The
free-running current detected by the "partner" device must therefore be added to the actual internal
field current K0266 with P612.02 in order to determine the total motor field current (indicated by
parameter r035).
The following settings are consequently required on the master and the standby master for the
redundancy mode of the field supply in addition to the parameters specified in the table in Section
6.3.2.2:
P082 <> 0
P612.02 = 6024 (Addition of receive word 4 to actual field current controller value)
U804.04 = 266
U804.09 = 266
The parameters described above enable the field current to continue flowing without interruption if
one device fails (fuse blown in the armature or field power section, appearance of a fault
message).
NOTE
An intact paralleling connection is essential for the redundancy mode of the field supply and the
electronics supply voltage for the master and the standby master must likewise be intact.
If redundancy of the field supply needs to be maintained even if the electronics supply voltage for
the master or the standby master fails, the total actual motor field current must be externally
sensed. This value must be fed to the master and the standby master by means of P612.
Notes on commissioning:
• The following parameters must be identically set on the master and the standby master in
addition to the above-mentioned parameters, after all the necessary connections have been
made: P076.02, P078.02.
• The field supply must be optimized on the master. Optimization runs must be started on the
master device for this purpose (current controller optimization run, ..., recording of field
characteristics). All slaves must be connected and ready to run when optimization is started.
After the field supply for the master has been optimized, the following master parameters must be
read and set to the same values on the standby master: P081, P102, P103, P112, P115 to P139,
P255, P256, P275, P276 as well as all field-specific settings that may have been made (see
Section 8, Function diagrams, Sheets G165 and G166).
Siemens AG 6RX1700-0AD76
SIMOREG DC Master Operating Instructions
(Operating mode for field)
(Send word 4 if master device is active, actual internal field current)
(Send word 4 after "master" function transferred to standby master, actual
internal field current)
Connections
6-25