ABB Relion 670 series - Page 210

2
Vm Vn
ZPHS
In
-
=
- ×
EQUATION1813-ANSI V1 EN-US (Equation 50)
Vm is the leading phase voltage, Vn the lagging phase voltage and In the phase current in the
lagging phase n.
The operation characteristic is shown in figure
84.
ANSI05000670-2-en.vsd
X1
R
X
0.5·RFltFwdPP
Kr·X1
Kr·X1
X1
60 deg
60 deg
0.5·RFltFwdPP
0.5·RFltRevPP
0.5·RFltRevPP
0.5·RFltRevPP
1
Kr
tan(60 deg)
=
0.5·RFltFwdPP
)/( phaseW
)/( phaseW
ANSI05000670 V2 EN-US
Figure 84: 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 51 or
equation
52.
03I IMinPUPG<
EQUATION2109-ANSI V1 EN-US (Equation 51)
Section 7 1MRK 502 066-UUS B
Impedance protection
204
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