ABB RED650 - Page 602

U
A
I
A
p Z
L
I
FA
D
A
--------
R
F
×+× ×=
EQUATION98 V1 EN-US (Equation 81)
Table 417: Expressions for U
A
, I
A
and I
FA
for different types of faults
Fault type: U
A
I
A
I
FA
L1-N U
L1A
I
L1A
+ K
N
x I
NA
3
2
---
D I
L1A
I
0A
–( )´
EQUATION110 V1 EN-US
L2-N
U
L2A
I
L2A
+ K
N
x I
NA
3
2
---
D I
L2A
I
0A
–( )´
EQUATION111 V1 EN-US
L3-N
U
L3A
I
L3A
+ K
N
x I
NA
3
2
--- D I
L3A
I
0A
–( )´
EQUATION112 V1 EN-US
L1-L2-L3, L1-L2,L1-L2-
N
U
L1A
-U
L2A
I
L1A
- I
L2A
DI
L1L2 A
EQUATION113 V1 EN-US
L2-L3, L2-L3-N U
L2A
-U
L3A
I
L2A
- I
L3A
DI
L2L3A
EQUATION114 V1 EN-US
L3-L1, L3-L1-N
U
L3A
-U
L1A
I
L3A
- I
L1A
DI
L3L1A
EQUATION115 V1 EN-US
The K
N
complex quantity for zero-sequence compensation for the single line is
equal to:
K
N
Z
0L
Z
1L
–
3 Z
1L
×
------------------------
=
EQUATION99 V1 EN-US (Equation 82)
DI is the change in current, that is the current after the fault minus the current
before the fault.
In the following, the positive sequence impedance for Z
A
, Z
B
and Z
L
is inserted
into the equations, because this is the value used in the algorithm.
For double lines, the fault equation is:
U
A
I
A
p Z
1L
I
FA
D
A
--------
R
F
I
0P
Z
0M
×+×+× ×=
EQUATION100 V1 EN-US
(Equation 83)
Where:
I
0P
is a zero sequence current of the parallel line,
Z
0M
is a mutual zero sequence impedance and
D
A
is the distribution factor of the parallel line, which is:
Section 15 1MRK 505 394-UEN A
Monitoring
596 Line differential protection RED650 2.2 IEC
Technical manual