GE L60, Инструкция по эксплуатации, Страница: 333 / 498

GE Multilin L60 Line Phase Comparison Relay 6-17
6 ACTUAL VALUES 6.4 RECORDS
6
and neglecting shunt parameters of the line:
(EQ 6.3)
Inserting the I
A
and I
B
equations into the V
A
equation and solving for the fault resistance yields:
(EQ 6.4)
Assuming the fault components of the currents, I
AF
and I
BF
are in phase, and observing that the fault resistance, as imped-
ance, does not have any imaginary part gives:
(EQ 6.5)
where: Im() represents the imaginary part of a complex number. Solving the above equation for the unknown m creates the
following fault location algorithm:
(EQ 6.6)
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
0
is the zero sequence compensation factor (for the first six equations above)
• 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.
Figure 6–5: FAULT LOCATOR SCHEME
I
B
I
BF
I
Apre
– =
R
F
V
A
m Z I
A
⋅ ⋅
–
I
AF
1
I
BF
I
AF
--------
+
⎝ ⎠
⎛ ⎞
⋅
-----------------------------------
=
Im
V
A
m Z I
A
⋅ ⋅
–
I
AF
-----------------------------------
⎝ ⎠
⎛ ⎞
0
=
m
Im V
A
I
AF
∗
⋅ ( )
Im Z I
A
I
AF
∗
⋅ ⋅ ( )
----------------------------------------
=
I
AF
I
A
I
Apre
– =
V
A
V
A
A
=
, I
A
I
A
A
K
0
I
0 A
⋅
+ =
V
A
V
A
B
=
, I
A
I
A
B
K
0
I
0 A
⋅
+ =
V
A
V
A
C
=
, I
A
I
A
BC
K
0
I
0 A
⋅
+ =
V
A
V
A
A
V
A
B
– =
, I
A
I
A
A
I
A
B
– =
V
A
V
A
B
V
A
C
– =
, I
A
I
A
B
I
A
C
– =
V
A
V
A
C
V
A
A
– =
, I
A
I
A
C
I
A
A
– =
SETTING
SETTING
FAULT REPORT
SOURCE:
SHOT # FROM
AUTO RECLOSURE
FAULT REPORT
TRIG:
I
A
3 _0
I
I
C
I
B
SRC X 50DD OP
VA
VC
VB
827094A4.CDR
Off=0
AND
FAULT
LOCATOR
RUN
0
3 SEC
ACTUAL VALUES
DATE
TIME
FAULT TYPE
FAULT LOCATION
FAULT# RECLOSE SHOT
FAULT REPORT #