ABB REL670 2.2 IEC, Applications Manual

Page: 315 / 908

If the denominator in equation 253 is called B and Z0m is simplified to X0m, then
the real and imaginary part of the reach reduction factor for the overreaching zones
can be written as:
( )
( )
( ) ( )
2 2
0 Re
Re 0 1
Re Im
X m B
K
B B
×
= -
+
EQUATION1427 V2 EN-US
(Equation 254)
( )
( )
( ) ( )
2 2
0 Im
Im 0
Re Im
X m B
K
B B
×
=
+
EQUATION1428 V2 EN-US
(Equation 255)
Parallel line is out of service and earthed in both ends
GUID-AEF4E5D3-A486-4DC7-8B95-83AADE67F966 v1
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-earth 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 256)
X
0E
X
0
1
X
m0
2
R
0
2
X
0
2
+
--------------------------
–
è ø
ç ÷
æ ö
×
=
EQUATION562 V1 EN-US
(Equation 257)
8.9.3.6 Setting of reach in resistive direction
GUID-3BFE80FD-8A51-4B71-8762-73DFA73AB28B v2
Set the resistive independently for each zone.
Set separately the expected fault resistance for phase-to-phase faults RFPP and for
the phase-to-earth 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-earth 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
258 .
 
1
R 2 R1Zx R0Zx RFPEZx
3
   
IECEQUATION2303 V2 EN-US
(Equation 258)
1MRK 506 369-UEN B
Section 8
Impedance protection
Line distance protection REL670 2.2 IEC 309
Application manual