ABB Relion 670 series - Phase-to-ground fault

PHSEL = AG*1+BG*2+CG*4+AB*8+BC*16+CA*32
6.10.2.1 Phase-to-ground fault
Index PHS in images and equations reference settings for Phase
selection, quadrilateral characteristic with settable angle (FRPSPDIS,
21).
( , )
( , )
PHSn
VA B C
IA B C
Z =
EQUATION1554 V1 EN (Equation 64)
where:
n corresponds to the particular phase (n=1, 2 or 3)
The characteristic for FRPSPDIS (21) function at phase-to-ground fault is according to
figure 102. The characteristic has a settable angle for the resistive boundary in the first
quadrant of 70°.
The resistance RN and reactance XN are the impedance in the ground-return path
defined according to equation
27 and equation 28.
0 1
3
R PE R PE
RN
-
=
EQUATION-2125 V1 EN (Equation 65)
0 1
3
R R
RN
-
=
EQUATION1256 V1 EN (Equation 65)
0 1
3
X X
XN
-
=
EQUATION1257 V1 EN (Equation 66)
1MRK505222-UUS C Section 6
Impedance protection
329
Technical reference manual