ABB Relion 650 Series Technical Manual page 224

Section 6
Current protection
6.14.5 Settings
Table 140: BRCPTOC (46) Group settings (basic)
Name Values (Range)
Operation Disabled
Enabled
Pickup_ub 50 - 90
Pickup_PH 5 - 100
tOper 0.000 - 60.000
Table 141: BRCPTOC (46) Non group settings (basic)
Name Values (Range)
GlobalBaseSel 1 - 6
6.14.6 Monitored data
Table 142: BRCPTOC (46) Monitored data
Name
IUNBAL
6.14.7 Operation principle
Broken conductor check (BRCPTOC, 46) detects a broken conductor condition by detecting the
asymmetry between currents in the three phases. The current-measuring elements continuously
measure the three-phase currents.
The current asymmetry signal output PICKUP is set on if:
• The difference in currents between the phase with the lowest current and the phase with the
highest current is greater than set percentage
• The lowest phase current is below 50% of the minimum setting value
The third condition is included to avoid problems in systems involving parallel lines. If a conductor
breaks in one phase on one line, the parallel line will experience an increase in current in the same
phase. This might result in the first two conditions being satisfied. If the unsymmetrical detection
lasts for a period longer than the set time
The simplified logic diagram of the broken conductor check function is shown in figure
BRCPTOC (46) is disabled (blocked) if:
218
Unit Step
- -
%IM 1
%IB 1
s 0.001
Unit Step
- 1
Type Values (Range)
REAL -
tOper the TRIP output is activated.
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Default Description
Disabled Operation Disable / Enable
50 Unbalance current operation value in
percent of max current
20 Minimum phase current for operation of
pickup_ub> in % of Ibase
5.000 Operate time delay
Default Description
1 Selection of one of the Global Base Value
groups
Unit Description
- Measured unbalance of phase currents
Pickup_ub of the highest phase current
1MRK 506 326-UUS B
PID-1123-SETTINGS v5
PID-1123-MONITOREDDATA v7
SEMOD171791-5 v4
Pickup_PH
116
Line distance protection REL650
Technical manual