ABB RELION REX640 Technical Manual page 1418

Condition monitoring functions
faults)/ reactive power (for excitation faults) falls below 2% of nominal value, the
OPERATE output is activated to open the generator circuit breaker.
In case the active or reactive power does not fall below 2% of nominal value within
the set
outputs respectively, the EXTERNAL_FLT output is activated along with OPERATE
output.
The opening of the generator circuit breaker is monitored through the inputs
GCB_CLOSED and GCB_OPEN. If the confirmation of GCB opening is not obtained
with in the set
the OPR_TIE_A and OPR_TIE_B outputs are activated to trip the tie breakers and
GCB_TRP_FAIL output is activated.
If any of the inputs GEN1_DATA ... GEN8_DATA indicate that backup protection is
triggered in one of the generators in its own subnetwork, then the module activates
the outputs OPR_TIE_A and OPR_TIE_B after the set
the local diesel generator from tripping due to faults in other network generators.
The module continues to monitor the tie breaker status through inputs
TIE_A_CLOSED, TIE_A_OPEN, TIE_B_CLOSED and TIE_B_OPEN. If after another
Max CB trip delay , the confirmed opening information of tie breakers is not
obtained then the module activates TIE_TRP_FAIL output.
The information on tie A or tie B side breaker tripping failure is shared with other
DGMGAPC functions in the network through output GEN_DATA to initiate tripping
of tie breaker. If the DGMGAPC function receives tie breaker trip failure indication
from a generator which shares a tie breaker with the local generator, then the
module initiates tripping of that shared tie breaker through either or both outputs
OPR_TIE_A and OPR_TIE_B to protect the local generator.
The activated binary outputs, OPERATE, OPR_TIE_A, OPR_TIE_B and
EXTERNAL_FLT, will remain active unless the RESET input is activated either from
LHMI or through communication.
The module combines the binary information, namely, the GCB status, adjacent tie
breaker statuses, Governor Mode, AVR mode, Generator local mode information,
backup protection activation (BCKUP_PRT_ST), fault status of the generator
(PRE_TRIP activation), A or B side tie breaker trip failure indication into output
GEN_DATA. This output is available in the monitored data and is communicated
to other DGMGAPC functions in the network on GOOSE. The active and reactive
power inputs of the local generator are also communicated over GOOSE for usage
as inputs in other DGMGAPC functions.
The binary input BLOCK can be used to block the function, for example, during
synchronization of switchboard sections and when the engine is placed in manual
control. The activation of the BLOCK input deactivates all module binary outputs,
binary monitored data and resets the internal timers.
7.5.6 Application
The function is intended towards a set of diesel generators with similar
characteristics interconnected with busbar and tie-breakers.
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Operate delay time , after the activation of STOP_ENGINE or DE_EXCITE
Min active power , Max active power , Min reactive power and Max
The
reactive power settings should be set such that the faulty generator
is tripped by its own DGMGAPC function before a healthy generator is
tripped on over/under power/excitation condition.
Max CB trip delay , from the instant of activating OPERATE output,
1MRS759142 F
Backup delay time , to protect
Technical Manual
REX640