ABB RED615 Technical Manual page 192

Section 4
Protection functions
186
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 and operating quantity I
BC
GUID-65CFEC0E-0367-44FB-A116-057DD29FEB79 V1 EN
Figure 90: Two-phase short circuit, short circuit is between phases B and C
Cross-polarizing as polarizing quantity
Table 197: Equations for calculating angle difference for cross-polarizing method
Faulte Used Used
d fault polarizing
phase current voltage
s
A I U
A BC
B I U
B CA
C I U
C AB
A - B I - I U -
A B BC
U
CA
B - C I - I U -
B C CA
U
AB
C - A I - I U -
C A AB
U
BC
The angle difference between the polarizing quantity U
I is marked as φ in an example of the phasors in a single-phase earth fault where
A
- I in the self-polarizing method.
B C
Angle difference
ANGLE A _ ( U ) -
ϕ
=
BC
GUID-4F0D1491-3679-4B1F-99F7-3704BC15EF9D V3 EN
_ ( ) -
ANGLE B U
ϕ
=
CA
GUID-F5252292-E132-41A7-9F6D-C2A3958EE6AD V3 EN
ANGLE C _ ( U ) -
ϕ
=
AB
GUID-84D97257-BAEC-4264-9D93-EC2DF853EAE1 V3 EN
ANGLE A _ ( U
ϕ
=
BC
GUID-AFB15C3F-B9BB-47A2-80E9-796AA1165409 V2 EN
ANGLE B _ ( U
ϕ
=
CA
GUID-C698D9CA-9139-40F2-9097-007B6B14D053 V2 EN
ANGLE C _ ( U
ϕ
=
AB
GUID-838ECE7D-8B1C-466F-8166-E8FE16D28AAD V2 EN
1YHT530004D05 D
o
( I ) - 90
ϕ ϕ
+
RCA
A
o
( ) - 90
I
ϕ ϕ
+
RCA
B
o
( I ) - 90
ϕ ϕ
+
RCA
C
- U ) - ( I - I ) -
ϕ ϕ
A B
CA
- U ) - ( I - I ) -
ϕ ϕ
AB B C
- U ) - ( I - I ) -
ϕ
BC C A
and operating quantity
BC
Technical Manual
o
90
+
RCA
o
90
+
RCA
o
90
ϕ
+
RCA
615 series