13-40
Testing and Troubleshooting
Date Code 20011205
SEL-311B Instruction Manual
(
)
(
)
A
0
k
M
0
k
1
MG
2
Z
Z
0
k
1
Z
TEST
AG
Ð
+
×
=
=
+
×
Equation
13.14
(
)
(
)
°
Ð
=
°
-
Ð
×°
Ð
=
°
-
Ð
+
×°
Ð
=
42
.
82
15
.
16
Z
55
.
1
725
.
1
97
.
83
36
.
9
Z
69
.
3
726
.
0
1
97
.
83
36
.
9
Z
TEST
TEST
TEST
I
A
must lag V
A
by the angle of Z
TEST
to check the maximum reach of the element
under test. With V
A
applied at an angle of 0°, the angle of I
A
is:
°
-
Ð
=
42
.
82
5
.
2
I
A
Calculate the magnitude of V
A
using Equation 13.15
ondary
sec
volts
0
.
0
4
.
40
V
42
.
82
15
.
16
42
.
82
5
.
2
V
Z
I
V
A
A
TEST
A
A
°
Ð
=
°
Ð
×
°
-
Ð
=
×
=
Equation
13.15
Select
.
volts
120
67
V
and
volts
120
67
V
C
B
°
Ð
=
°
-
Ð
=
With the above settings, the ground distance elements are supervised by the
negative-sequence directional element. It is important to check the negative-
sequence quantities applied and verify that the 32GF element should assert allowing
the forward-reaching distance element to operate. Calculate the magnitude and angle
of negative-sequence voltage and current applied for the test quantities listed above.
Then calculate the negative-sequence impedance, Z2c, applied using Equation 13.1
and compare Z2c to the Z2FT threshold that is a function of the Z2F setting and
Z2m.
(
)
(
)
C
B
2
A
3
1
2
C
B
2
A
3
1
2
I
a
I
a
I
I
V
a
V
a
V
V
×
+
×
+
×
=
×
+
×
+
×
=
(
)
[
]
2
2
2
2
I
*
I
ANG
1
Z
1
V
Re
c
2
Z
×
°
Ð
×
=
Equation
13.1
2
2
I
V
m
2
Z
=
m
2
Z
25
.
0
F
2
Z
25
.
1
FT
2
Z
×
-
×
=
Taking the test signals from Table 13.4.
°
Ð
=
°
-
Ð
=
°
Ð
=
120
V
0
.
67
V
120
V
0
.
67
V
0
V
4
.
40
V
C
B
A
(
)
volts
180
88
.
8
V
volts
120
0
.
67
120
1
120
0
.
67
240
1
0
4
.
40
V
2
3
1
2
°
Ð
=
°
Ð
×
°
Ð
+
°
-
Ð
×
°
Ð
+
°
Ð
×
=
Summary of Contents for SEL-311B
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