ABB Relion 670 series - Page 253

ANSI06000383-3-en.vsd
ANSI06000383 V3 EN-US
Figure 114: Definition of fault sectors for phase-to-phase fault
The phase-to-phase loop for the faulty phases will be determined if the angle between the
sequence voltages V
2
and V
1
lies within the sector defined according to figure 114 and the
following conditions are fulfilled:
|V
1
|> V1MinOP
|V
2
|> V2MinOp
where:
V1MinOP and V2MinOp are the setting parameters for positive sequence and negative
sequence minimum operate voltages
The positive sequence voltage V
1
A in figure 114 above is reference.
If there is a three-phase fault, there will not be any release of the individual phase signals, even if
the general conditions for V
2
and V
1
are fulfilled.
Phase-to-ground and phase-to-phase-to-ground-fault detection
SEMOD153832-135 v5
The detection of phase-to-ground and phase-to-phase-to-ground fault (US patent 5390067) is
based on two conditions:
1. Angle relationship between V
2
and I
0
2. Angle relationship between V
2
and V
1
The condition 1 determines faulty phase at single phase-to-ground fault by evaluating the angle
between V
2
and I
0
.
1MRK 502 066-UUS B Section 7
Impedance protection
247
Technical manual