ABB RELION 620 Series Technical Manual page 181

1MAC504801-IB E
620 series ANSI
Technical Manual
In an example of the phasors in a two-phase short-circuit failure where the fault is between
the phases B and C, the angle difference is measured between the polarizing quantity V
and operating quantity I
B
GUID-8D3A8A1A-C78B-46F7-A102-DCB1A6BD60D6-ANSI V1 EN
Figure 78: Two-phase short circuit, short circuit is between phases B and C
The equations are valid when network rotating direction is counter-
clockwise, that is, ABC. If the network rotating direction is reversed, 180
degrees is added to the calculated angle difference. This is done
automatically with a system parameter Phase rotation.
- I marked as φ.
C
Section 4
Protection functions
AB
175