ABB Relion 670 Series Technical Reference Manual page 299

1MRK505222-UUS C
Technical reference manual
|3V |>V | · 0.2
0 1
|V |> VBase · 0.2/√(3)
1
and
3I <0.1 · IBase
0
or
3I <maxIph · INRelPG
0
where:
3V is the magnitude of the zero sequence voltage
0
V is the magnitude of the negative sequence voltage at the relay measuring point of
2
phase A
k5 is design parameter
ILmax is the maximal phase current
IMinOp
is the setting of minimum operate phase current in % of
Phase-to-phase fault detection
The detection of phase-to-phase fault is performed by evaluation of the angle
difference between the sequence voltages V
C-A sector
VB
180°
A-B sector
ANSI06000383 V2 EN
Figure 149: Definition of fault sectors for phase-to-phase fault
and V .
2 1
60°
VC
0°
VA (Ref)
B-C sector
VA
300°
ANSI06000383-2-en.vsd
Section 6
Impedance protection
IBase
293