Siemens 7SC80 Manual page 123

Pickup Measuring element
A
Current
B, N —
C, N —
A, B
Ι
A
B, C —
AC
Ι
A
A, B, N
Ι
A
B, C, N —
A, C, N
Ι
A
A, B, C
Ι
A
A, B, C, N
Ι
A
1) or 3 · V = |V
0 A
Direction Determination of Directional Phase Elements
As already mentioned, the direction determination is performed by determining the phase angle between the
fault current and the reference voltage. In order to satisfy different network conditions and applications, the
reference voltage can be rotated by an adjustable angle. In this way, the vector of the rotated reference
voltage can be closely adjusted to the vector of the fault current in order to provide the best possible result for
the direction determination.
based on a single-phase ground fault in Phase A. The fault current Ι
. The reference voltage, in this case V
ϕ
sc
1519 ROTATION ANGLE, positively counter-clockwise. In this case, a rotation by +45°.
[7sj6x_drehung-referenzspannung-phase-200904-he, 1, en_US]
Figure 2-31
The rotated reference voltage defines the forward and reverse area, see
range of ±86° around the rotated reference voltage V
device detects forward direction. In the mirrored area, the device detects reverse direction. In the intermediate
area, the direction result is undefined.
SIPROTEC Compact, 7SC80, Manual
E50417-G1140-C486-A8, Edition 07.2017
B
Voltage Current
—
Ι
B
— —
V - V
Ι
B C B
—
Ι
B
V - V —
B C
V - V
Ι
B C B
—
Ι
B
V - V —
B C
V - V
Ι
B C
B
V - V
Ι
B C B
+ V + V |, depending on the connection type of voltages
B C
Figure 2-31 clearly shows the relationship for the directional phase element
for the directional phase element A, is rotated by the setting value
BC
Rotation of the reference voltage, directional phase element
2.3 Directional Overcurrent Protection 67, 67N
C
Voltage Current Voltage
V - V — —
C A
— V
Ι
A
C
V - V — —
C A
V - V V
Ι
C A C A
— V
Ι
A
C
V - V — —
C A
V - V V
Ι
C A C A
— V
Ι
C A
V - V V
Ι
C A A
C
V - V V
Ι
C A C A
follows the fault voltage by fault angle
scA
Figure
If the vector of the fault current is in this area, the
ref,rot
Functions
ground
Current Voltage
Ι V 1)
N N
- V
Ι V 1)
B
N N
— —
- V — —
B
- V — —
B
V 1)
Ι
N
N
- V
V 1)
Ι
B N
N
- V
V 1)
Ι
B N
N
- V — —
B
- V
Ι V 1)
B N
N
2-32. The forward area is a
123