ABB REB650 Technical Manual page 312

Section 12
Monitoring
306
I
= × × + ×
V I p Z FA
A A 1L
D
A
EQUATION1600 V1 EN
Where:
I is a zero sequence current of the parallel line,
0P
Z is a mutual zero sequence impedance and
0M
D is the distribution factor of the parallel line, which is:
A
( ) × (
1 p – Z
---------------------------------------------------------------------------- -
D =
A
×
2 Z
A
EQUATION101 V1 EN
The K compensation factor for the double line becomes:
N
Z – Z Z
0L 1L 0M
×
----------------------- - ---------------- -
K = +
N
× ×
3 Z 3 Z
1L 1L
EQUATION102 V1 EN
From these equations it can be seen, that, if Z
equation for a single line is obtained. Only the distribution factor differs in these two
cases.
Because the D distribution factor according to equation
A
general equation 63 can be written in the form:
2
× ×
p p K K K R
– + – =
1 2 3 F
EQUATION103 V1 EN
Where:
V Z
= +
K A B
1
× +
I Z Z Z
A L L ADD
EQUATION1601 V1 EN
æ
V Z
= ×
K A B
ç
2
× +
I Z Z Z
è
A L L ADD
EQUATION1602 V1 EN
+ ×
R I Z
F 0P 0M
)
+ Z + Z + Z
A A L B B
×
Z 2 Z
+ +
L B
I
0P
-------
I
0A
= 0, then the general fault location
0m
0
+
1
ö
+
1
÷
ø
1MRK 505 277-UUS C
(Equation 63)
(Equation 64)
61 or 63 is a function of p, the
(Equation 65)
(Equation 66)
(Equation 67)
Technical Manual