ABB RELION 620 Series Technical Manual page 275

1MRS757644 F
620 series
Technical Manual
faulted phase is phase A. The polarizing quantity is rotated with 90 degrees. The
characteristic angle is assumed to be ~ 0 degrees.
GUID-6C7D1317-89C4-44BE-A1EB-69BC75863474 V1 EN
Figure 130: 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 and operating quantity I
AB
Protection functions
- I marked as φ.
B C
Section 4
269