Self-polarizing as polarizing method
Table 260: Equations for calculating angle difference for self-polarizing method
Faulted
phases
Used
fault
current
Used
polarizing
voltage
Angle difference
A
I
A
U
A
ANGLE
A
U
I
A
A
RCA
_
(
) -
(
) -
=
ϕ
ϕ
ϕ
B
I
B
U
B
ANGLE
B
U
I
B
B
RCA
_
(
) -
(
) -
=
ϕ
ϕ
ϕ
C
I
C
U
C
ANGLE
C
U
I
C
C
RCA
_
(
) -
(
) -
=
ϕ
ϕ
ϕ
A - B
I
A
- I
B
U
AB
ANGLE
A
U
I
I
AB
A
B
RCA
_
(
) -
(
-
) -
=
ϕ
ϕ
ϕ
B - C
I
B
- I
C
U
BC
ANGLE
B
U
I
I
BC
B
C
RCA
_
(
) -
(
-
) -
=
ϕ
ϕ
ϕ
C - A
I
C
- I
A
U
CA
ANGLE
C
U
I
I
CA
C
A
RCA
_
(
) -
(
-
) -
=
ϕ
ϕ
ϕ
In an example case of the phasors in a single-phase earth fault where the faulted
phase is phase A, the angle difference between the polarizing quantity U
A
and
operating quantity I
A
is marked as φ. In the self-polarization method, there is no
need to rotate the polarizing quantity.
Figure 124: Single-phase earth fault, phase A
In an example case of a two-phase short-circuit failure where the fault is between
phases B and C, the angle difference is measured between the polarizing quantity U
BC
and operating quantity I
B
- I
C
in the self-polarizing method.
Protection functions
1MRS758755 C
244
REC615 & RER615
Technical Manual
Содержание Relion REC615
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