ABB RELION REX640, Техническое руководство, Страница: 1682 / 1960

Figure 907: Example of an auto-initiation sequence with synchronization failure in
the first shot and circuit breaker closing failure in the second shot
In the first shot, the synchronization condition is not fulfilled (
SYNC
is FALSE). When
the auto wait timer elapses, the sequence continues to the second shot. During the
second reclosing, the synchronization condition is fulfilled and the close command
is given to the circuit breaker after the second reclose time has elapsed.
After the second shot, the circuit breaker fails to close when the wait close time has
elapsed. The third shot is started and a new close command is given after the third
reclose time has elapsed. The circuit breaker closes normally and the reclaim time
starts. When the reclaim time has elapsed, the sequence is concluded successful.
9.9.6.2 Sequence
The auto reclose sequence is implemented by using CBBs. The highest possible
amount of CBBs is seven. If the user wants to have, for example, a sequence of three
shots, only the first three CBBs are needed. Using building blocks instead of fixed
shots gives enhanced flexibility, allowing multiple and adaptive sequences.
Each CBB is identical. The
Shot number CBB_ setting defines at which point in the
auto-reclose sequence the CBB should be performed, that is, whether the particular
CBB is going to be the first, second, third, fourth or fifth shot.
During the initiation of a CBB, the conditions of initiation and blocking are checked.
This is done for all CBBs simultaneously. Each CBB that fulfils the initiation
conditions requests an execution.
The function also keeps track of shots already performed, that is, at which point the
auto-reclose sequence is from shot 1 to lockout. For example, if shots 1 and 2 have
already been performed, only shots 3 to 5 are allowed.
Additionally, the
Enable shot jump setting gives two possibilities:
• Only such CBBs that are set for the next shot in the sequence can be accepted
for execution. For example, if the next shot in the sequence should be shot 2, a
request from CBB set for shot 3 is rejected.
• Any CBB that is set for the next shot or any of the following shots can be
accepted for execution. For example, if the next shot in the sequence should
be shot 2, also CBBs that are set for shots 3, 4 and 5 are accepted. In other words,
shot 2 can be ignored.
Control functions 1MRS759142 F
1682 REX640
Technical Manual