Setting Of Zones For Parallel Line Application - ABB REL670 2.2 IEC Applications Manual

Section 8
Impedance protection
8.5.3.5
278
( )
³ × -
Zrev 1.2 ZL Z rem 2
EQUATION1525 V5 EN-US
Where:
ZL is the protected line impedance
Z2rem is zone2 setting at remote end of protected line
In some applications it might be necessary to consider the enlarging factor due to
fault current infeed from adjacent lines in the reverse direction in order to obtain
certain sensitivity.

Setting of zones for parallel line application

Parallel line in service – Setting of zone1
With reference to section
85% of protected line.
Parallel line in service – setting of zone2
Overreaching zones (in general, zones 2 and 3) must overreach the protected circuit
in all cases. The greatest reduction of a reach occurs in cases when both parallel
circuits are in service with a single phase-to-earth fault located at the end of a
protected line. The equivalent zero-sequence impedance circuit for this case is
equal to the one in figure
The components of the zero-sequence impedance for the overreaching zones must
be equal to at least:
R = R + R
0E 0 m0
EQUATION553 V1 EN-US
X = X + X
0E 0 m0
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:
Z 0
m
= -
K 0 1
× + +
2 Z 1 Z 0 R
f
EQUATION1426 V1 EN-US
If the denominator in equation
the real and imaginary part of the reach reduction factor for the overreaching zones
can be written as:
"Parallel line applications", the zone reach can be set to
138 in section "Parallel line
208 is called B and Z0m is simplified to X0m, then
1MRK 506 369-UEN B
(Equation 205)
applications".
(Equation 206)
(Equation 207)
(Equation 208)
Line distance protection REL670 2.2 IEC
Application manual
SEMOD154704-48 v1
SEMOD154704-50 v1
SEMOD154704-53 v2