ABB REG670 Applications Manual page 581

1MRK 502 071-UEN -
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Application manual
Table 62: Blockings without setting possibilities
Activation
Disconnected
transformer
(automatically reset)
No Master/More than one
Master (automatically
reset)
One transformer in a
parallel group switched to
manual control
(automatically reset)
Communication error
(COMMERR) (automatic
deblocking)
Circulating current method
Mutual blocking
When one parallel instance of voltage control TR8ATCC blocks its operation, all
other TR8ATCCs working in parallel with that module, shall block their operation as
well. To achieve this, the affected TR8ATCC function broadcasts a mutual block to
the other group members via the horizontal communication. When mutual block is
received from any of the group members, automatic operation is blocked in the
receiving TR8ATCCs that is, all units of the parallel group.
The following conditions in any one of TR8ATCCs in the group will cause mutual
blocking when the circulating current method is used:
Type of blocking Description
Auto Block Automatic control is blocked for a transformer when
parallel control with the circulating current method is
used, and that transformer is disconnected from the
LV-busbar. (This is under the condition that the setting
OperHoming is selected Off for the disconnected
transformer. Otherwise the transformer will get into the
state Homing). The binary input signal DISC in
TR1ATCC or TR8ATCC function shall be used to
supervise if the transformer LV circuit breaker is closed
or not. The outputs TRFDISC and AUTOBLK will be
activated . Blocking will be removed when the
transformer is reconnected (input signal DISC set back
to zero).
Auto Block Automatic control is blocked when parallel control with
the master-follower method is used, and the master is
disconnected from the LV-busbar. Also if there for
some reason should be a situation with more than one
master in the system, the same blocking will occur. The
binary input signal DISC in TR1ATCC or TR8ATCC
function shall be used to supervise if the transformer
LV circuit breaker is closed or not. The outputs
TRFDISC, MFERR and AUTOBLK will be activated.
The followers will also be blocked by mutual blocking in
this situation. Blocking will be removed when the
transformer is reconnected (input signal DISC set back
to zero).
Auto Block When the setting
control will be blocked when parallel control with the
master-follower or the circulating current method is
used, and one of the transformers in the group is
switched from auto to manual. The output AUTOBLK
will be activated.
Auto block If the horizontal communication (GOOSE) for any one
of TR8ATCCs in the group fails it will cause blocking of
automatic control in all TR8ATCC functions, which
belong to that parallel group. This error condition will be
reset automatically when the communication is re-
established. The outputs COMMERR and AUTOBLK
will be set.
Section 15
Control
OperationAdapt is " Off ", automatic
575