K
N
Z
0L
Z
1L
–
3 Z
1L
×
------------------------
=
EQUATION99 V1 EN (Equation 185)
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:
FA
A A 1L F 0P 0M
A
I
V I p Z R I Z
D
= × × + × + ×
EQUATION1600 V1 EN (Equation 186)
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:
D
A
1 p–( ) Z
A
Z
AL
Z
B
+ +( ) Z
B
+×
2 Z
A
Z
L
2 Z
B
×+ +×
-----------------------------------------------------------------------------
=
EQUATION101 V1 EN
The K
N
compensation factor for the double line becomes:
K
N
Z
0L
Z
1L
–
3 Z
1L
×
------------------------
Z
0M
3 Z
1L
×
-----------------
I
0P
I
0A
-------
×+=
EQUATION102 V1 EN (Equation 187)
From these equations it can be seen, that, if Z
0m
= 0, then the general fault location
equation for a single line is obtained. Only the distribution factor differs in these two
cases.
Because the D
A
distribution factor according to equation 184 or 186 is a function of p,
the general equation 186 can be written in the form:
EQUATION103 V1 EN
(Equation 188)
1MRK505222-UUS C Section 15
Monitoring
943
Technical reference manual
To Next Page
Loading...
