ABB Relion 630 Series, Technical Manual

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q = Bad q = Good
Load-shedding blocking = TRUE
t T
0 T 2 T
3 T
4 T
5 T
Load-shedding blocking = FALSE
GUID-AC44FCB5-C8E0-4CF2-9608-CB82879B1244 V1 EN
Figure 132: Logic for load-shedding blocking status at the time of measurement
cycle
q = Bad q = Good
Load-shedding blocking = FALSE
0
T 2 T
3 T
4 T
5 T
Load-shedding blocking = TRUE
GUID-82D266F7-DA92-4661-B1BA-8AC28635BD1F V1 EN
Figure 133: Logic for load-shedding blocking status within the measurement
cycle
Where
q CB_IED_QVAL
T, 2T, 3T Measurement cycle
t Time between the change of CB_IED_QVAL input from “Bad” to “Good” and the next
measurement cycle.
If the
IED_TST_MODE
input is TRUE or the
CB_POSITION
input is "Invalid”, or
the
CB_POSITION
input remains in the “Intermediate” position for more than the CB
Interm time setting, the load-shedding blocking status is TRUE.
The load-shedding blocking status is reported to the General logic module, Fast load-
shedding trigger logic module, Slow load-shedding logic module, Over current based
load-shedding module and Demand based load-shedding module.
1MRS757256 F
Section 7
Power management functions
PML630/Compact Load-Shedding Solution 219
Technical Manual