ABB RELION 650 Series Applications Manual page 123

1MRK 505 363-UEN A
zero sequence impedance circuit for this case is equal to the one in figure
line in service.
The components of the zero sequence impedance for the overreaching zones must be equal to
at least:
R =
0E
EQUATION553 V1 EN-US
X =
0E
EQUATION554 V1 EN-US
Check the reduction of a reach for the overreaching zones due to the effect of the zero
sequence mutual coupling. The reach is reduced for a factor:
= -
K 0 1
EQUATION1426 V1 EN-US
If the denominator in equation
imaginary part of the reach reduction factor for the overreaching zones can be written as:
( )
Re K 0
EQUATION1427 V2 EN-US
( )
Im 0
K
EQUATION1428 V2 EN-US
Parallel line is out of service and earthed in both ends
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
EQUATION561 V1 EN-US
X =
0E
EQUATION562 V1 EN-US
Application manual
R + R
0 m0
X + X
0 m0
Z 0
m
× + +
2 Z 1 Z 0 R
f
( )
×
X m 0 Re B
= -
1
( ) ( )
2 2
+
Re B Im B
( )
×
X m 0 Im B
=
( ) ( )
2 2
+
Re B Im B
2
æ ö
X
m0
× ç ÷
R 1 + ------------------------- -
0
2 2
è ø
R + X
0 0
2
æ ö
X
m0
×
X ç 1 – ------------------------- - ÷
0
2 2
è ø
R + X
0 0
61 is called B and Z0m is simplified to X0m, then the real and
Section 7
Impedance protection
58 in section Parallel
(Equation 59)
(Equation 60)
(Equation 61)
(Equation 62)
(Equation 63)
GUID-345B36A6-B5FB-46DD-B5AE-81A1599FFC6E v1
(Equation 64)
(Equation 65)
117