ABB 615 Series - Page 251

Negative sequence voltage as polarizing quantity
When the negative voltage is used as the polarizing quantity, the angle difference between
the operating and polarizing quantity is calculated with the same formula for all fault
types:
ANGLE X V I
RCA
_ ( ) ( )= − − − ϕ ϕ ϕ 2 2
GUID-7AC132D5-033D-468F-ADB6-7E04C3C7E153-ANSI V1 EN (Equation 5)
This means that the actuating polarizing quantity is -V2.
GUID-41DF2169-686B-4564-98D5-B09F7F6BBEA0-ANSI V1 EN
Figure 120: Phasors in a single-phase ground fault, phases A-N, and two-phase short
circuit, phases B and C, when the actuating polarizing quantity is the
negative-sequence voltage -V2
Positive sequence voltage as polarizing quantity
Table 241: Equations for calculating angle difference for positive-sequence quantity polarizing method
Faulted
phases
Used fault
current
Used
polarizing
voltage
Angle difference
A I
A
V1
ANGLE A V I
A
RCA
_ ( ) ( )= − − ϕ ϕ ϕ 1
GUID-7BCB8B12-2484-49AD-92A3-839A39BE5D01-ANSI V1 EN
B I
B
V1
ANGLE B V I
B
RCA
_ ( ) ( )= − − − ϕ ϕ ϕ 1 120
o
GUID-E4D7718C-A73E-46C6-89A6-8EEFDBEAB046-ANSI V1 EN
C
I
C
V1
ANGLE C V I
C
RCA
_ ( ) ( )= − − + ϕ ϕ ϕ 1 120
o
GUID-6BCAA5DE-778A-4623-B196-2433045A5B2A-ANSI V1 EN
Table continues on next page
1MAC059074-MB A Section 4
Protection functions
615 series ANSI 245
Technical Manual