ABB Relion 670 series - Three-Phase Faults

0 max
100
3
INBlockPP
IphI < ×
EQUATION2110-ANSI V1 EN-US (Equation 52)
where:
IMinPUPG is the minimum operation current for ground measuring loops,
3I0BLK_PP is 3I
0
limit for blocking phase-to-phase measuring loop and
Iphmax is maximal magnitude of the phase currents.
7.2.6.3 Three-phase faults
M13140-80 v4
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.
0.5·RFltFwdPP·K3
X1·K3
90 deg
0.5·RFltRevPP·K3
30 deg
R (ohm/phase)
X (ohm/phase)
4 X1
3
×
2 RFltFwdPP
3
×
ANSI05000671-4-en.vsd
2
K3
3
=
ANSI05000671 V4 EN-US
Figure 85: The characteristic of FDPSPDIS (21) for three-phase fault (setting parameters in
italic)
1MRK 502 066-UUS B Section 7
Impedance protection
205
Technical manual