ABB RELION RET670, Applications Manual

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( )
( )
( ) ( )
2 2
0 Im
Im 0
Re Im
X m B
K
B B
×
=
+
EQUATION1428 V2 EN-US
(Equation 290)
Parallel line is out of service and grounded in both ends
GUID-345B36A6-B5FB-46DD-B5AE-81A1599FFC6E 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-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 291)
X
0E
X
0
1
X
m0
2
R
0
2
X
0
2
+
-------------------------- –
è ø
ç ÷
æ ö
×
=
EQUATION562 V1 EN-US
(Equation 292)
8.12.3.6 Setting the reach with respect to load
GUID-ED84BDE6-16CD-45ED-A45D-5CFB828A9040 v6
Set separately the expected fault resistance for phase-to-phase faults RFPPZx and for
the phase-to-ground faults RFPGZx for each zone. For each distance zone, set all
remaining reach setting parameters independently of each other.
The final reach in the 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
293 .
( )
1
R 2 R1 R0 RFPG
3
= × + +
ANSIEQUATION2303 V1 EN-US
(Equation 293)
2 X1Zx X0Zx
arctan
2 R1Zx R0Zx
loop

 

 
 
 
 
EQUATION2304 V2 EN-US
(Equation 294)
Section 8
1MRK 504 163-UUS A
Impedance protection
388 Transformer protection RET670 2.2 ANSI
Application manual