ABB REL650 series Technical Manual page 161

1MRK 506 335-UUS A
Technical manual
Forward
200°
Reverse
IEC06000385 V1 EN
Figure 69: Directional element used to release the measured angle between V
I
0
The input radians are summarized with an offset angle and the result evaluated. If the angle
is within the boundaries for a specific sector, the phase indication for that sector will be
active see figure 68. Only one sector signal is allowed to be activated at the same time.
The sector function for condition 1 has an internal release signal which is active if the main
sequence function has classified the angle between V
conditions must be fulfilled for activating the release signals:
|V |>V2MinOp
2
|3I |> 0.05 · IBase
0
|3I |>maxIph · INRelPG
0
where:
V and 3I
2 0
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
and the positive sequence voltage V
there is no need for shifting phases if the fault is in reverse direction. A phase shift is
20°
en06000385.vsd
are the magnitude of the negative sequence voltage and zero-
sequence current (3I )
0
is the setting parameter for minimum operating negative sequence
voltage
is the maximum phase current
. Since this is a phase-to-phase voltage relationship,
1
Section 6
Impedance protection
and I as valid. The following
0 0
and
o
2
155