Schweitzer Engineering Laboratories SEL-311A, Instruction Manual

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13-40 Testing and Troubleshooting Date Code 20011205
SEL-311A 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 × =