ABB RELION RET670, Applications Manual

Page: 285 / 1016

( )
( )
( ) ( )
2 2
0 Im
Im 0
Re Im
X m B
K
B B
×
=
+
EQUATION1428 V2 EN-US
(Equation 141)
Parallel line is out of service and grounded in both ends
SEMOD55087-77 v3
Apply the same measures as in the case with a single set of setting parameters. This
means that an underreaching zone must not overreach the end of a protected circuit for
the single phase-to-ground faults.
Set the values of the corresponding zone (zero-sequence resistance and reactance)
equal to:
R
0E
R
0
1
X
m0
2
R
0
2
X
0
2
+
--------------------------
+
è ø
ç ÷
æ ö
×
=
EQUATION561 V1 EN-US
(Equation 142)
X
0E
X
0
1
X
m0
2
R
0
2
X
0
2
+
-------------------------- –
è ø
ç ÷
æ ö
×
=
EQUATION562 V1 EN-US
(Equation 143)
8.3.3.6 Setting of reach in resistive direction
SEMOD55087-84 v7
Set the resistive reach R1 independently for each zone.
Set separately the expected fault resistance for phase-to-phase faults RFPP and for the
phase-to-ground faults RFPE for each zone. For each distance zone, set all remaining
reach setting parameters independently of each other.
The final reach in resistive direction for phase-to-ground fault loop measurement
automatically follows the values of the line-positive and zero-sequence resistance, and
at the end of the protected zone is equal to equation
144 .
 
1
R 2 R1Zx R0Zx RFPEZx
3
   
IECEQUATION2303 V2 EN-US
(Equation 144)
2 X1Zx X0Zx
arctan
2 R1Zx R0Zx
loop

 

 
 
 
 
EQUATION2304 V2 EN-US
(Equation 145)
1MRK 504 163-UUS A
Section 8
Impedance protection
Transformer protection RET670 2.2 ANSI 279
Application manual