ABB RELION 670 Series Technical Manual page 255

1MRK 502 066-UUS B
where:
V and IN
2
V2MinOp
maxIph
The angle difference is phase shifted by 180 degrees if the fault is in reverse direction.
The condition 2 looks at the angle relationship between the negative sequence voltage V
positive sequence voltage V
for shifting phases if the fault is in reverse direction. A phase shift is introduced so that the fault
sectors will have the same angle boarders as for condition 1. If the calculated angle between V
and V lies within one sector, the corresponding phase for that sector will be activated. The
1
condition 2 is released if both the following conditions are fulfilled:
V2MinOp
|V |>
2
V1MinOp
|V |>
1
where:
|V | and |V
1
V1MinOP and V2MinOP
140°
AG sector
ANSI06000413 V1 EN-US
Figure 117: Condition 2: V
If both conditions are true and there is sector match, the fault is deemed as single phase-to-
ground. If the sectors, however, do not match the fault is determined to be the complement of the
second condition, that is, a phase-to-phase-to- ground fault.
Technical manual
are the magnitude of the negative sequence voltage and zero-
sequence current (3I
is the setting parameter for minimum operating negative
sequence voltage
is the maximum phase current
. Since this is a phase-to-phase voltage relationship, there is no need
1
| are the magnitude of the positive and negative sequence voltages.
2
are the setting parameters for positive sequence and negative sequence
minimum operating voltages.
CG sector
BG sector
260°
en06000413_ansi.vsd
and V
2
)
0
20°
V1A
(Ref)
angle relationship
1
Section 7
Impedance protection
and the
2
2
249