1MAC309294-MB F Section 4
Protection functions
RER620 109
Technical Manual
Figure 46: Two-phase short circuit, short circuit is between phases B and C
Cross-polarizing as polarizing quantity
Table 130: Equations for calculating angle difference for cross-polarizing method
The polarizing quantity is rotated with 90 degrees. The characteristic angle is assumed to
be ~ 0 degrees.
Faulted
phases
Used
fault
current
Used
polarizing
voltage
Angle difference
AI
A
V
BC
BI
B
V
CA
CI
C
V
AB
A - B I
A
- I
B
V
BC
-
V
CA
B - C I
B
- I
C
V
CA
-
V
AB
C - A I
C
- I
A
V
AB
-
V
BC
ANGLE A V I
BC
A
RCA
o
_()-()- =+
90
ANGLE B V I
CA
B
RCA
o
_()-()- =+
90
ANGLE C V I
AB
C
RCA
o
_()-()- =+
90
ANGLE A V V I I
BC CA
AB
RCA
o
_(-)-(-)- =+
90
ANGLE B V V I I
CA AB
BC
RCA
o
_(-)-(-)- =+
90
ANGLE C V V I I
AB BC
CA
RCA
o
_(-)-(-)- =+
90
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