ABB RELION REX640 Technical Manual page 563

1MRS759142 C
REX640
Technical Manual
• Small steady state line charging current
• In-zone transformer no load current
• Impact of tap changer positions
The timer is activated according to the calculated differential, stabilizing current and
the set differential characteristic.
PROT_ACTIVE
ENABLE OPERATION
(from Fail safe function)
BLOCK_LS
I_DIFF
(from Differential calculation)
I_BIAS
(from Differential calculation)
BLKD2H_LOC
(from Inrush detector)
BLKD2H_REM
(from Inrush detector)
End section 1
Slope section 2
End section 2
Slope section 3
Low operate value
GUID-2909B3F2-F66B-41FA-9363-07C68F35E049 V1 EN
Figure 303: Operation logic of the stabilized low stage
The stabilization affects the operation of the function.
GUID-FAF022AD-E4E1-4D36-9B72-30D7B776A9FC V1 EN
Figure 304: Operating characteristics of the protection. (LS) stands for the low
stage and (HS) for the high stage.
The slope of the operating characteristic curve of the differential function varies in the
different sections of the range:
Charact.
I
I
bias
Operating curve type
Operate delay time
Reset delay time
Minimum operate
time
Time multiplier
Section 4
Protection functions
Timer
OPR_LS_LOC
t
t
STR_LS_LOC
557