Setting Of Reverse Zone; Setting Of Zones For Parallel Line Application - ABB RELION 650 Series Applications Manual

Section 7
Impedance protection
V
Z =
AF
I
EQUATION302 V5 EN-US
IEC09000256 V2 EN-US
Figure 64: Setting of overreaching zone
7.1.3.4

Setting of reverse zone

The reverse zone is applicable for purposes of scheme communication logic, current reversal
logic, weak-end infeed logic, and so on. The same applies to the back-up protection of the bus
bar or power transformers. It is necessary to secure, that it always covers the overreaching
zone, used at the remote line IED for the telecommunication purposes.
Consider the possible enlarging factor that might exist due to fault infeed from adjacent lines.
Equation
blocking scheme, weak-end infeed, and so on.
³
Zrev
EQUATION1525 V5 EN-US
Where:
ZL
Z2rem
In many 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.
7.1.3.5

Setting of zones for parallel line application

Parallel line in service – Setting of zone 1
With reference to section
protected line.
However, influence of mutual impedance has to be taken into account.
Parallel line in service – setting of zone 2
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
116
I + I I
A A C
= Z + ⋅ Z +
AC CF
I
A A
Z
AC
A
I
A
Z<
58 can be used to calculate the reach in reverse direction when the zone is used for
( )
× -
1.2 ZL Z rem 2
is the protected line impedance
is zone 2 setting at remote end of protected line.
"Parallel line

+ I + I
A C B
⋅ R = Z + 1

AC
F
I

A
Z
CB
F
C
Z
CF
I + I
A C
I
C
applications", the zone reach can be set to 85% of the
  
I I + I
C C B
+  ⋅ Z + 1 +  ⋅

C F F
I I
  
A A
I
B
B
IEC09000256-2-en.vsd
GUID-B633CF2C-28B2-4FDD-BE0E-D09CA434F01F v1
GUID-4E0C3824-41B6-410F-A10E-AB9C3BFE9B12 v1
GUID-8A62367C-2636-4EC1-90FF-397A51F586F7 v1
GUID-98D11A72-C5BE-4C67-ADB5-95124C2AF987 v1
1MRK 505 363-UEN A
R
F
(Equation 57)
(Equation 58)
Application manual