103
Line differential protection (DIFL)
&KDSWHU
9HULI\LQJVHWWLQJVE\VHFRQGDU\
LQMHFWLRQ
,QFUHDVHWKHWKUHHSKDVHYROWDJHWRLWVUDWHGYDOXH
Read the values of the differential and bias currents under the
menu:
6HUYLFH5HSRUW'LII9DOXHV
They must correspond to the value:
(Equation 8)
The bias currents are available under the same menu. They must
be equal to the measured differential current in each phase.
'LVFRQQHFWWKHYROWDJHVIURPWKHWHUPLQDODQGFRQQHFWRQO\
RQHSKDVHWRDOOWKUHHYROWDJHLQSXWVRIWKHWHUPLQDO
,QFUHDVHWKHPHDVXUHGYROWDJHWRWKHUDWHGSKDVHYDOXHDQG
REVHUYHWKHYDOXHVRIWKHGLIIHUHQWLDODQGELDVFXUUHQWVSUH
VHQWHGRQWKHWHUPLQDO
They must correspond to the following values:
(Equation 9)
(Equation 10)
I
Diff
= I
Bias
for each phase.
U
Represents measured phase voltage.
IDiffL1
IDiffL2
IDiffL3
U
XC1 CTFactor
⋅
--------------------------------------------
=
=
=
IDiffL1
IDiffL2
IDiffL3
2 U
⋅
XC0 CTFactor
⋅
--------------------------------------------
=
=
=
IBiasL1
IBiasL2
IBiasL3
U
XC0 CTFactor
⋅
--------------------------------------------
=
=
=
Summary of Contents for REL 531
Page 16: ...10 Note signs KDSWHU 6DIHW LQIRUPDWLRQ ...
Page 44: ...38 Checking the binary I O circuits KDSWHU KHFNLQJ WKH H WHUQDO FLUFXLWU ...
Page 52: ...46 Checking the self supervision signals KDSWHU QHUJLVLQJ WKH WHUPLQDO ...
Page 140: ...134 Testing the interaction of the distance protection KDSWHU 7HVWLQJ WKH SURWHFWLRQ V VWHP ...
