ABB REL650 - Page 58

, ,
,
2 1 0.85 ( )
1
1 0.85 1 ( )
8 3.2 17.5
17.5 0.85 10 48.0
8
B C
A B set
A B
source B source A A B
A B set
source B
I
Z Z Z B C
I
Z Z Z
Z Z B C
Z
-
-
-
-
-
£ + × - × =
+ +
= + × - × =
+ +
= + × × = W
GUID-CD674B2B-8DA2-4614-A12E-0BE6E3EF7ACF V1 EN (Equation 11)
This corresponds to about 2.7 times the line reactance.
An alternative way is to set Z2 according to:
Z2 ≥ Z1
A-B
+ 0.85 · Z
set
(B-C) = 17.5 + 0.85 · 10 = 26.0 Ω
If remote back–up protection is used in the network it is desirable to maximize reach
of zone 2.
If local back-up protection is used it is better to minimize the zone 2 reach.
The settings can be chosen:
,
2 2.5 2.5 2.5 17.5 44.2
Line posseq
Z Z j= × = × + = W
GUID-60425379-F1D0-4370-8F6D-37874DE5BBBA V1 EN (Equation 12)
4. Set
RFPP2 to 44.00 Ω, if CharPPZ2 is set to Quadrilateral.
It is assumed that the fault resistance is equal to the fault resistances calculated for
zone 1. At a fault on an adjacent line also the fault resistance is influenced by the fault
current infeed from the other lines connected to B. The apparent value of the fault
resistance at A can approximately be calculated as:
1
3 2 8 17 5
2 17 9
3 2
source,B source,A A B
B C
f f
A B source,B
X X X
I
RFPP R R
I X
. .
.
.
-
-
-
+ +
= × = × =
+ +
= × = W
GUID-B39F72C7-DDED-495F-9DD4-55CA75A1EB0F V1 EN (Equation 13)
This is the minimum value for the fault resistance reach RFPP2 setting. It can be
valuable to have much higher RFPP setting. RFPP2 ≈ Z2 setting is proposed:
5. Set RFPG2 to 100 Ω, if CharPGZ2 is set to Quadrilateral.
, ,
,
1
3.2 8 17.5
11.1 99.6
3.2
source B source A A B
B C
f f
A B source B
X X X
I
RFPE R R
I X
-
-
-
+ +
= × = × =
+ +
= × = W
GUID-9D945B7C-AC4C-4C4A-92A3-503D283000BA V1 EN (Equation 14)
This is the minimum value for the fault resistance reach RPG2 setting. It can be
valuable to have much higher RFPG2 setting. RFPG2 ≈ 2.3 · Z2 setting is proposed
(should never be larger than 4.5 · X2 where X2 is the reactive part of Z2):
6. Set OpModetPGZ2 to Enabled.
Section 3 1MRK 506 334-UUS A
REL650 setting examples
52
Application manual