Setting Notes - Siemens SIPROTEC 7SJ62 Manual

Functions
2.1 General

2.1.6.2 Setting Notes

Definition of Nominal Rated Values
At addresses 1101 FullScaleVolt. and 1102 FullScaleCurr., the primary reference voltage (phase-
to-phase) and reference current (phase) of the protected equipment is entered (e.g. motors). If these reference
sizes match the primary nominal values of the VTs and CTs, they correspond to the settings in address 202
and 204 (Section 2.1.3.2). They are generally used to show values referenced to full scale.
Ground Impedance Ratios (only for Fault Location)
The adjustment of the ground impedance ratio is only important for the utilization of the line fault location func-
tion. This is done by entering the resistance ratio RE/RL and the reactance ratio XE/XL.
The values under addresses 1103 and 1104 apply if only one line section is available and to all faults that occur
outside the defined line sections.
If several line sections are set, the following shall apply:
• for line section 1, addresses 6001 and 6002
• for line section 2, addresses 6011 and 6012
• for line section 3, the addresses 6021 and 6022.
Resistance ratio RE/RL and reactance ratio XE/XL are calculated formally and do not correspond to the real
and imaginary components of Z
line data using the following formulas:
Where
R
0
X
0
R
1
X
1
This data can be used for the entire line or line section, or as distance-related values, since the quotients are
independent of the distance.
Calculation example:
20 kV free line 120 mm
/s = 1.42 Ω /mile
R
0
/s = 2.03 Ω/mile
X
0
/s = 0.39 Ω/km
R
1
/s = 0.55 Ω/km
X
1
56
/Z . No complex calculation is required! The ratios can be obtained from the
E L
– Zero sequence resistance of the line
– Zero sequence reactance of the line
– Positive sequence resistance of the line
– Positive sequence reactance of the line
2
with the following data:
Zero resistance
Zero reactance
Positive sequence resistance
Positive sequence reactance
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008