Siemens siprotec SJ62 User Manual page 103

2 Functions
Direction Determi-
nation of Direction-
al Ground Element
with Negative Se-
quence Values
101
Figure 2-26) or V . The fault current -3I
N
and follows the fault voltage 3V
through the setting value 1619 ROTATION ANGLE. In this case, a rotation of -45°.
Figure 2-26 Rotation of the reference voltage, directional ground element with zero se-
quence values
The forward area is also a range of ±86° around the rotated reference voltage V
If the vector of the fault current -3I
direction.
Figure 2-27 shows the treatment of the reference voltage for the directional ground
element using the negative sequence values based on a single-pole ground fault in
Phase A. As reference voltage, the negative sequence system voltage is used, as
current for the direction determination, the negative sequence system current, in
which the fault current is displayed. The fault current -3I
fault current I and follows the voltage 3V
scA
voltage is rotated through the setting value 1619 ROTATION ANGLE. In this case, a
rotation of -45°.
Figure 2-27 Rotation of the reference voltage, directional ground element with negative se-
quence values
is in phase oposition to the fault current I
0
by the fault angle ϕ
. The reference voltage is rotated
0 sc
(or I ) is in this area, the device detects forward
0 N
by the fault angle ϕ
2
C53000-G1140-C147-A, Edition 07.2015
is in phase oposition to the
2
. The reference
sc
SIPROTEC 4, 7SJ62/63/64 Handbuch
scA
.
ref, rot