Functions
6-177SA522 Manual
C53000-G1176-C119-2
6.1.3 General Protection Data
General protection data (3RZHU6\VWHP'DWD36\VWHP'DWD) includes
settings associated with all functions rather than a specific protective or monitoring
function. In contrast to the 3RZHU6\VWHP'DWD36\VWHP'DWD as dis-
cussed in Sub-section 6.1.1, these settings can be changed over with the setting
groups. To modify these settings, select the 6(77,1*6 menu option *URXS$ (setting
group A), and then 3RZHU6\VWHP'DWD36\VWHP'DWD.
The other setting groups are *URXS%*URXS&, and *URXS', as described in
Subsection 6.1.2.
System starpoint
(neutral)
The device is suited to systems with an earthed system starpoint (effective or low im-
pedance earthed).
Rating of the
Protected Plant
The rated primary voltage (line voltage) and rated primary current (phase) of the pro-
tected plant are entered in the address )XOO6FDOH9ROW and
)XOO6FDOH&XUU. These parameters influence the display of the operational meas-
ured values in percent. If these ratings correspond to those of the voltage and current
transformers, the settings are the same as those in address and (Section
6.1.1).
General Line Data The settings of the line data in this case refers to the common data which is independ-
ent on the actual distance protection grading.
The line angle (Address /LQH$QJOH) may be derived from the line parameters.
The following applies:
where R
L
being the resistance and X
L
the reactance of the protected feeder. The line
parameters may either apply to the entire line length, or be per unit of line length as
the quotient is independent of length. Furthermore it makes no difference is the quo-
tients were calculated with primary or secondary values.
Calculation example:
110 kV overhead line 150 mm
2
with the following data
R’
1
= 0.19 Ω/km
X’
1
= 0.42 Ω/km
The line angle is computed as follows
In address 1105 the setting /LQH$QJOH = ° is entered.
ϕ
tan
X
L
R
L
-------
=
ϕ
arc
X
L
R
L
-------
tan
=
or
tan
ϕ
X
L
R
L
-------
X’
1
R’
1
--------
0.42
Ω
/km
0.19
Ω
/km
-----------------------------
2.21
== = =
ϕ
65.7°
=
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