GE D30 Instruction Manual page 311

6 ACTUAL VALUES
and neglecting shunt parameters of the line:
Inserting the I and I equations into the V
A B
Assuming the fault components of the currents, I
ance, does not have any imaginary part gives:
where: Im() represents the imaginary part of a complex number. Solving the above equation for the unknown m creates the
following fault location algorithm:
where * denotes the complex conjugate and
Depending on the fault type, appropriate voltage and current signals are selected from the phase quantities before applying
the two equations above (the superscripts denote phases, the subscripts denote stations).
For AG faults:
For BG faults:
For CG faults:
For AB and ABG faults:
For BC and BCG faults:
For CA and CAG faults:
where K is the zero sequence compensation factor (for the first six equations above)
0
For ABC faults, all three AB, BC, and CA loops are analyzed and the final result is selected based upon consistency of the
results
The element calculates the distance to the fault (with m in miles or kilometers) and the phases involved in the fault.
The relay allows locating faults from delta-connected VTs. If the
and the VTs are connected in wye, the fault location is performed based on the actual phase to ground voltages. If the VTs
are connected in delta, fault location is suspended.
If the
FAULT REPORT 1 VT SUBSTITUTION
location is performed based on the actual phase to ground voltages. If the VTs are connected in a delta configuration, fault
location is performed based on the delta voltages and externally supplied neutral voltage:
GE Multilin
I I I
= –
B BF Apre
equation and solving for the fault resistance yields:
A
V m Z I ⋅ ⋅
–
A A
R
-----------------------------------
=
F
I
⎛ ⎞
BF
⋅
I 1 ------- -
+
⎝ ⎠
AF
I
AF
and I are in phase, and observing that the fault resistance, as imped-
AF BF
⋅ ⋅
V m Z I
–
⎛ ⎞
A A
-----------------------------------
Im 0
=
⎝ ⎠
I
AF
∗
( ⋅ )
Im V I
A AF
m --------------------------------------- -
=
∗
Im Z I ( ⋅ ⋅ I )
A AF
I I I .
= –
AF A Apre
A A
V V , I I K ⋅ I
= = +
A A A A 0 0A
B B
⋅
V V , I I K I
= = +
A A A A 0 0A
C BC
⋅
V V , I I K I
= = +
A A A A 0
A B A
V V V , I I I
= – = –
A A A A A
B C B
V V V , I I I
= – = –
A A A A A
C A C
V V V , I I I
= – = –
A A A A A
FAULT REPORT 1 VT SUBSTITUTION
setting value is "V0" and the VTs are connected in a wye configuration, the fault
D30 Line Distance Relay
0A
B
A
C
A
A
A
setting is set to "None",
6.4 RECORDS
(EQ 6.3)
(EQ 6.4)
6
(EQ 6.5)
(EQ 6.6)
(EQ 6.7)
(EQ 6.8)
(EQ 6.9)
(EQ 6.10)
(EQ 6.11)
(EQ 6.12)
6-19