Siemens SIPROTEC 7SJ62 Manual page 275

Loop Selection
Using the pickup of the time overcurrent protection (directional or non-directional), the valid measurement loops
for the calculation of fault impedance are selected.
Table 2-19 shows the assignment of the evaluated loops to the possible pickup scenarios of the protection el-
ements.
Table 2-19
Pickup by
A B C
x
x
x
x
x
x
x x
x x
x x
x x
x x
x x
x x x
x x x
Output of Fault Location
The following information is outout as result of the fault location:
• the short-circuit loop from which the fault reactance was determined,
• the fault reactance X in Ω primary and Ω secondary,
• the fault resistance R in Ω primary and Ω secondary,
• the distance to fault d in kilometers or miles of the line proportional to the reactance, converted on the basis
of the set line reactance per unit line length,
• the distance to fault d in % of the line length, calculated on the basis of the set reactance per unit length and
the set line length.
Line Sections
The line type is determined by the line section settings. If, for instance, the line includes a cable and an over-
head line, two different sections must be configured. The system can distinguish between up to three different
line types. When configuring this line data, please note that the different tabs for setting the line sections will
only be displayed if more than one line section has been configured under the functional scope (address 181).
The parameters for a line section are entered in the Setting tab .
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008
Assignment of Pickup - evaluated Loops
fault type measured loop
N
A A-N
B B-N
C C-N
x N A-N, B-N, C-N
x A-N A-N
x B-N B-N
x C-N C-N
A-B A-B
A-C A-C
B-C B-C
x A-B-N A-B, A-N, B-N
x A-C-N C-A, A-N, B-N
x B-C-N B-C, B-N, C-N
A-B-C A-B, B-C, C-A
x A-B-C-N A-B, B-C, C-A, A-N, B-N, C-N
Functions
2.15 Fault Locator
signaled loop
A-N
B-N
C-N
lowest impedance
A-N
B-N
C-N
A-B
A-C
B-C
Lowest impedance
Lowest impedance
Lowest impedance
lowest impedance
lowest impedance
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