Siemens siprotec SJ62 User Manual page 57

2 Functions
Reactance Setting
(only for Fault Lo-
cation)
55
Calculation Example:
20 kV overhead line 120 mm
/s = 0.39 Ω/mile
R
1
/s = 0.58 Ω/mile
X
1
/s = 1.42 Ω/mile
R
0
/s = 2.03 Ω/mile
X
0
For ground impedance ratios, the following result:
These values are set at addresses 1103 and 1104 respectively.
The reactance setting must only be entered if using the line fault location function. The
reactance setting enables the protective relay to indicate the fault location in terms of
distance.
The reactance value X' is entered as a value x' at address 1105 in Ω per mile if set
to distance unit Miles (address 215, see Section 2.1.3.2 "Distance Unit") , or at
address 1106 in Ω per kilometer if set to distance unit km. If the setting of address 215
is modified after entry of a reactance value at address 1105 or 1106, the reactance
value must be modified and reentered accordingly.
When using the PC and DIGSI for configuration, these values can also be entered as
primary values. The following conversion to secondary values is then not relevant.
For calculation of primary values in terms of secondary values the following applies in
general:
Likewise, the following goes for the reactance setting of a line:
with
N
CTR
N
VTR
2
with the following data:
Positive sequence resistance
Positive sequence reactance
Zero sequence resistance
Zero sequence reactance
— Current transformer ratio
— Voltage transformer ratio
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015