Three-Phase Faults - ABB RELION 670 Series Technical Manual

1MRK 502 066-UUS B
INBlockPP
<
3 I
0
100
EQUATION2110-ANSI V1 EN-US
where:
IMinPUPG
3I0BLK_PP is 3I
Iphmax
7.2.6.3

Three-phase faults

The operation conditions for three-phase faults are the same as for phase-to-phase fault, that is
equation , equation and equation are used to release the operation of the function.
However, the reach is expanded by a factor 2/√3 (approximately 1.1547) in all directions. At the
same time the characteristic is rotated 30 degrees, counter-clockwise. The characteristic is shown
in figure 85.
2
=
K3
ANSI05000671 V4 EN-US
Figure 85: The characteristic of FDPSPDIS (21) for three-phase fault (setting parameters in
Technical manual
×
Iph max
is the minimum operation current for ground measuring loops,
limit for blocking phase-to-phase measuring loop and
0
is maximal magnitude of the phase currents.
X (ohm/phase)
×
4 X1
3
0.5·RFltFwdPP·K3
X1·K3
0.5·RFltRevPP·K3
3
italic)
90 deg
×
2 RFltFwdPP
3
R (ohm/phase)
30 deg
ANSI05000671-4-en.vsd
Section 7
Impedance protection
(Equation 52)
M13140-80 v4
205