Siemens siprotec SJ62 User Manual page 101

2 Functions
PICKUP
Current
A I
A
B —
C —
N —
A, N
I
A
B, N —
C, N —
A, B I
A
B, C —
A, C
I
A
A, B, N I
A
B, C, N —
A, C, N I
A
A, B, C
I
A
A, B, C, N
I
A
Direction Determi-
nation of Direction-
al Phase Elements
99
Figure 2-23 Cross-polarized voltages for direction determination
The following table shows the assignment of measured values for the determination
of fault direction for various types of pickups.
Table 2-6 Measured values for the determination of fault direction
A
Voltage Current
V – V —
B C
—
I
B
— —
— —
V – V —
B C
— I
B
— —
V – V I
B C B
—
I
B
V – V —
B C
V – V I
B C B
—
I
B
V – V —
B C
V – V
I
B C B
V – V
I
B C B
1)
or 3 · V = |VA + VB + VC|, depending on type of connection for the voltages
0
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
through 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. Figure 2-24 clearly shows the relation-
ship for the directional phase elements based on a single-pole ground fault in Phase
A. The fault current I
scA
voltage, in this case V
Directional Element
B
Voltage Current
— —
V – V —
C A
— I
C
— —
— —
V – V —
C A
—
I
C
V – V —
C A
V – V
I
C A C
—
I
C
V – V —
C A
V – V
I
C A C
— I
C
V – V
I
C A C
V – V
I
C A C
follows the fault voltage by the fault angle ϕ
for the directional phase element A, is rotated through the
BC
C
Voltage Current
— —
— —
V – V —
A B
—
I
N
—
I
N
— I
N
V – V
I
A B N
— —
V – V —
A B
V – V —
A B
— I
N
V – V
I
A B N
V – V I
A B N
V – V —
A B
V – V
I
A B N
sc
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
N
Voltage
—
—
—
1)
V
N
1)
V
N
1)
V
N
1)
V
N
—
—
—
1)
V
N
V
N
1)
V
N
—
1)
V
N
. The reference