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Broken Line Protection
I
/I
> (46R)
2
1
Recorded values of the latest eight faults
Detailed information is available on the eight latest faults: Time
stamp, fault type, fault current, load current before the fault, elapsed
delay and setting group.
Table 3.7 – Recorded values of the directional overcurrent stages
(8 latest faults) I
>, I
>>, I
dir
dir
dir
Parameter
Value
yyyy-mm-dd
hh:mm:ss.ms
Type
1-N
2-N
3-N
1-2
2-3
3-1
1-2-3
Flt
Load
EDly
Angle
U1
SetGrp
1
2
The purpose of the broken line protection is to detect unbalanced
load conditions, for example a broken wire of a heavy loaded
overhead line in case there is no earth fault.
The operation of the unbalanced load function is based on the
negative phase sequence component I
phase sequence component I
currents using the method of symmetrical components. The
function requires that the measuring inputs are connected
correctly so that the rotation direction of the phase currents is as
shown in "Connection Examples" in Chapter 9. The unbalance
protection has definite time operation characteristic.
Protection Functions
>>>, I
>>>> (67)
dir
Unit
Description
Time stamp of the recording, date
Time stamp, time of day
Fault type
Ground fault
Ground fault
Ground fault
Two phase fault
Two phase fault
Two phase fault
Three phase fault
xIn
Maximum fault current
xIn
1 s average phase currents before the fault
%
Elapsed time of the operating time setting.
100% = trip
°
Fault angle in degrees
xUn
Positive sequence voltage during fault
Active setting group during fault
related to the positive
2
. This is calculated from the phase
1
3-15
857-UM001A-EN-P – July 2009
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