Functions
2.1 General
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
62
When determining the angle, the quadrant of the result must be considered. The following table indicates the
quadrant and range of the angle which is determined by the signs of the calculated real and imaginary part of
K
0
.
Table 2-2
Quadrants and ranges of the angle K
0
In this example the following result is obtained:
The magnitude and angle of the earth impedance (residual) compensation factors setting for the first zone Z1
and the remaining zones of the distance protection may be different. This allows the setting of the exact values
for the protected line, while at the same time the setting for the back-up zones may be a close approximation
even when the following lines have substantially different earth impedance factors (e.g. cable after an overhead
line). Accordingly, the settings for the address
1120
K0 (Z1)
and
1121
Angle K0(Z1)
are determined with
the data of the protected line, while the addresses
1122
K0 (> Z1)
and
1123
Angle K0(> Z1)
apply to
the remaining zones Z1B and Z2 up to Z6 (as seen from the relay location).
Note
If a combination of values is set which is not recognized by the device, it operates with preset values K
0
= 1 ·
e
0°
. The information
„Dis.ErrorK0(Z1)“
(No. 3654) or
„DisErrorK0(>Z1)“
(No. 3655) appears in the
event logs.
Level Arrangement
The location of the centre phase of a level arrangement is determined in address
1124
center phase
. The
compensation factor parameters
C0/C1
(address
1125
) and
center phase
are reserved for the double-
ended fault locator. They are used for configuration of a line with different sections (e.g. overhead line - cable
sections). See Section 2.21 for more details.
Parallel line mutual impedance (optional)
If the device is applied to a double circuit line (parallel lines) and parallel line compensation for the distance
and/or fault location function is used, the mutual coupling of the two lines must be considered. A prerequisite
for this is that the earth (residual) current of the parallel line has been connected to the measuring input
I
4
of
the device and that this was configured with the power system data (Section 2.1.2.1) by setting the appropriate
parameters.
Real part
Imaginary
part
tan
ϕ
(K0)
Quadrant/range
Calculation
+
+
+
I 0° ... +90°
arc tan (|Im| / |Re|)
+
–
–
IV –90° ... 0°
–arc tan (|Im| / |Re|)
–
–
+
III –90° ... –180°
arc tan (|Im| / |Re|) –180°
–
+
–
II +90° ... +180° –arc tan (|Im| / |Re|) +180°
