ABB RELION REX640 Technical Manual page 340

Section 4
Protection functions
334
FAULT_DIR gives the detected direction of the fault during fault situations, that is,
when the START output is active.
Self-polarizing as polarizing method
Table 370: Equations for calculating angle difference for self-polarizing method
Faulted Used fault Used
phases current polarizing
voltage
A I U
A A
B I U
B B
C I U
C C
A - B I - I U
A B AB
B - C I - I U
B C BC
C - A I - I U
C A CA
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
quantity I is marked as φ. In the self-polarization method, there is no need to rotate
A
the polarizing quantity.
Angle difference
ANGLE A _ ( U ) -
= ϕ
A
GUID-E915316C-5AA3-49F5-B5C7-5B0ADB27EF73 V1 EN
ANGLE B U
_ ( ) -
= ϕ
B
GUID-65A09723-6B3F-40CA-86D2-AFF080BC1D83 V1 EN
ANGLE C _ ( U ) -
= ϕ
C
GUID-4BBE8D29-689B-43D9-9331-3245E15D90AF V1 EN
ANGLE A U
_ ( ) -
= ϕ
AB
GUID-84EFEF02-5484-4E03-9128-1883596BE3DB V1 EN
ANGLE B _ ( U ) -
= ϕ
BC
GUID-75235DEE-77F7-4084-BDD8-99072DFF6937 V1 EN
ANGLE C U
_ ( ) -
= ϕ
CA
GUID-DAF7131F-CD11-4174-AEB4-A8145C2282D8 V1 EN
1MRS759142 C
( ) - I
ϕ ϕ
A
RCA
(Equation 8)
I
( ) -
ϕ ϕ
B RCA
(Equation 9)
( ) - I
ϕ ϕ
C
RCA
(Equation 10)
I I
( - ) -
ϕ ϕ
A B RCA
(Equation 11)
( - I I ) -
ϕ ϕ
B C
RCA
(Equation 12)
I I
( - ) -
ϕ ϕ
C A RCA
(Equation 13)
and operating
A
Technical Manual
REX640