ABB RELION REX640 Technical Manual page 343

1MRS759142 C
REX640
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 U and operating quantity I
AB
GUID-461EE2E5-8346-4E79-A824-CBF66711A356 V1 EN
Figure 190: 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.
Protection functions
- I marked as φ.
B C
Section 4
337