ABB Relion 650 Series Technical Manual page 94

Section 5
Impedance protection
The setting of the load encroachment function may influence the total operating characteristic,
(for more information, refer to section
The input DIRCND contains binary coded information about the directional coming from the
directional function (ZDNRDIR). It shall be connected to the STDIR output on ZDNRDIR. This
information is also transferred to the input DIRCND on the distance measuring zones, that is, the
ZQDPDIS block.
The STCNDZI or DLECND output contains, in a similar way as DIRCND, binary coded information, in
this case information about the condition for opening correct fault loop in the distance measuring
element. It shall be connected to the PHSEL input on the ZQDPDIS blocks.
5.2.6.1 Phase-to-ground fault
VA B C
=
Z
n
PHS
IA B C
EQUATION1554 V1 EN-US
where:
n
The characteristic for FDPSPDIS (21) function at phase-to-ground fault is according to figure 42.
The characteristic has a fixed angle for the resistive boundary in the first quadrant of 60°.
The resistance RN and reactance XN are the impedance in the ground-return path defined
according to equation
R 0
=
RN
EQUATION1256 V1 EN-US
X 0
=
XN
EQUATION1257 V1 EN-US
88
Index PHS in images and equations reference settings for Phase selection with load
encroachment function FDPSPDIS (21).
( , )
( , )
corresponds to the particular phase (n=1, 2 or 3)
4 and equation 5.
-
R 1
3
-
X 1
3
© Copyright 2011 ABB Power Grids. All rights reserved
"Load encroachment").
1MRK 506 326-UUS B
M13140-22 v3
(Equation 3)
(Equation 4)
(Equation 5)
Line distance protection REL650
Technical manual