GUID-BCCA5F2D-9FF7-4188-9B5D-DA05E8E80CC0 v1
Table 69. Average Power Transient Earth Fault Protection APPTEF
Function Range or value Accuracy
Minimum operate level for residual
overvoltage 3Uo> start condition "UN>"
(5-80)% of UBase ±0.5% of Ur
Reset ratio for residual overvoltage 3Uo> > 75% -
Operate time for residual overvoltage
3Uo>
at 0 to 2 x U
set
Min. = 5 ms
Max. = 15 ms
-
Minimum threshold level for residual
overcurrent start condition "IN>"
(3-100)% of lBase ±1.5% of Ir
Minimum operate level for integrated
current to declare the forward direction
"IMinForward”
(2.0-100.0)% of lBase ±1.5% of Ir
Minimum operate level for integrated
current to declare the reverse direction
"IMinReverse"
(2.0-100.0)% of lBase ±1.5% of Ir
Minimum time delay to declare EF
direction "tStart"
(0.04-2.00) s ±0.2% or ±25 ms whichever is greater
Minimum trip time delay "tTrip" (0.00-20.00) s ±0.2% or ±25 ms whichever is greater
Minimum pulse length duration for trip
and/or start outputs "tPulseMin"
(0.02-1.00) s ±0.2% or ±10 ms whichever is greater
Operate 3Io current level for cross country
fault detection "CrossCntry_IN>"
(20-1000)% of lBase ±1.0% of Ir at I ≤ Ir
±1.0% of I at I > Ir
Time delay to activate cross country fault
detection "tCC" at 0 to 2 x I
set
(0.02-1.00) s ±0.2% or ±25 ms whichever is greater
Drop off time delay to de-activate cross
country fault detection at 2 x I
set
to 0
Fixed 0.2 s ±0.2% or ±25 ms whichever is greater
Operate 3Io current level for circulating
current detection "Circulate_IN>"
(2-200)% of lBase ±1.0% of Ir at I ≤ Ir
±1.0% of I at I > Ir
Time delay to activate circulating current
detection "tCircIN" at 0 to 2 x I
set
(5.0-60.0) s ±0.2% or ±25 ms whichever is greater
Drop off time delay to de-activate
circulating current detection at 2 x I
set
to 0
Fixed 0.5 s ±0.2% or ±25 ms whichever is greater
Generator protection REG670
1MRK 502 074-BEN M
90 Hitachi Power Grids
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