ABB Relion 670 Series Technical Reference Manual page 230

Section 6
Impedance protection
224
0.5·RFltRevPP
60 deg
0.5·RFltRevPP
Kr·X1
0.5·RFltRevPP
ANSI05000670 V2 EN
Figure 103: The operation characteristics for FDPSPDIS (21) at phase-to-phase
fault (setting parameters in italic, directional lines drawn as "line-dot-dot-
line"), ohm/phase domain
In the same way as the condition for phase-to-ground fault, there are current conditions
that have to be fulfilled in order to release the phase-to-phase loop. Those are
according to equation 30
<
3I IMinPUPG
0
EQUATION2109-ANSI V1 EN
INBlockPP
< ×
3 I
Iph max
0
100
EQUATION2110-ANSI V1 EN
where:
IMinPUPG is the minimum operation current for ground measuring loops,
3I0BLK_PP is 3I
limit for blocking phase-to-phase measuring loop and
0
Iphmax is maximal magnitude of the phase currents.
W
( / phase )
X
0.5·RFltFwdPP
Kr·X1
0.5·RFltFwdPP
60 deg
X1
Kr
0.5·RFltFwdPP
ANSI05000670-2-en.vsd
or equation 31.
1MRK505222-UUS C
X1
W
( / phase )
R
1
=
tan(60 deg)
Technical reference manual
(Equation 30)
(Equation 31)