ABB Relion 620 Series - Page 311

Figure 156: Single-phase earth fault, phase A
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
AB
and operating quantity I
B
- I
C
marked as φ.
1MRS757644 H
Protection functions
620 series
Technical Manual
311