ABB RELION 630 Series Technical Manual page 288

Section 7
Power management functions
282
Depending on fast load-shed blocking signals received from NCBDCSWI,
NPMMXU functions and subnetwork number of busbars, the load-shed blocking for
particular subnetwork is calculated as follows.
The module receives the fast load-shed block signal
FLS_BLK_BB1...FLS_BLK_BB4 for busbar 1...4 from the NPMMXU function.
If any of the busbar fast load-shed block signal is active, the corresponding
subnetwork is blocked.
If the FLS_BLK_BB1 signal is active, the load-shed blocking is active for subnetwork
corresponding to BB1_SN_NO, for example, if FLS_BLK_BB1 is TRUE and
BB1_SN_NO = 1, subnetwork 1 load-shed blocking is active.
The module receives the fast load-shed block signals FLS_BLK_CB
blocking signals TST_BLK_CB
If FLS_BLK_CB is active or TST_BLK_CB
ij
busbar "i" and busbar "j" is blocked, for example, if FLS_BLK_CB12 is TRUE and
BB1_SN_NO = 1 and BB1_SN_NO = 2, subnetwork 1 and subnetwork 2 load-shed
blocking is active.
If the BLOCK input is TRUE, all subnetworks load-shedding blocking signal is active.
Figure 152 shows load-shed blocking signals for different subnetworks for various
conditions.
FLS_BLK_BB1
BB1_SN_NO
FLS_BLK_BB4
BB4_SN_NO
TST_BLK_CB
12
FLS_BLK_CB
12
BB1_SN_NO
BB2_SN_NO
TST_BLK_CB
56
FLS_BLK_CB
56
BB5_SN_NO
BB6_SN_NO
BLOCK
GUID-0A2AAEC0-773B-4C92-8728-15D0A92BAB87 V1 EN
Figure 152: Calculation of load-shed blocking signal for subnetworks
from the respective NCBDCSWI functions.
ij
is active, the subnetwork number of
ij
Subnetwork
LS block
calculation
Subnetwork
LS block
calculation
Subnetwork
LS block
calculation
Subnetwork
LS block
calculation
1MRS757256 F
and test mode
ij
LS_BLOCK1
OR
LS_BLOCK2
OR
LS_BLOCK3
OR
LS_BLOCK4
OR
PML630/Compact Load-Shedding Solution
Technical Manual