ABB 615 series Technical Manual page 251

1MAC059074-MB A
615 series ANSI
Technical Manual
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 2 )
= ϕ − − ϕ
GUID-7AC132D5-033D-468F-ADB6-7E04C3C7E153-ANSI V1 EN
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 Used fault Used
phases current polarizing
voltage
A I V1
A
B I V1
B
C I V1
C
Table continues on next page
( ) I 2
− ϕ
RCA
Angle difference
ANGLE A _ ( ) V 1
= ϕ
GUID-7BCB8B12-2484-49AD-92A3-839A39BE5D01-ANSI V1 EN
_ ( ) 1
ANGLE B V
= ϕ
GUID-E4D7718C-A73E-46C6-89A6-8EEFDBEAB046-ANSI V1 EN
ANGLE C _ ( ) V 1
= ϕ
GUID-6BCAA5DE-778A-4623-B196-2433045A5B2A-ANSI V1 EN
Protection functions
( I )
− ϕ − ϕ
RCA
A
o
( ) 120
I
− ϕ − ϕ −
RCA
B
o
( I ) 120
− ϕ − ϕ +
C RCA
Section 4
(Equation 5)
245