2.2 Distance Protection
59
7ST6 Manual
E50417-G1176-C251-A3
2.2.8
Zone Changeover (only for 16.7 Hz)
To adapt the protection to different switching states of the overhead contact line during
operation, the device is equipped with a changeover function of the impedance stages
for zone Z1, zone Z2 and zone Z3 via binary inputs, a control system or the operator
control panel.
Depending on the selected type of characteristic curve, this function switches the pa-
rameters for the reach of these zones to an alternative value.
With combined characteristics, the Z Stroke or Z Stroke Reverse parameters are then
used for these stages instead of the Z parameters. Likewise, the X Stroke or X Stroke
Reverse parameters instead of the X parameters are used for polygonal characteris-
tics. For the characteristics, the R Stroke or R Stroke Reverse parameters are used
instead of the R parameters.
The active control source for this changeover is selected with the parameter
1205
CHANGE ZONE
; setting options are
Binary Input
,
Protocol
,
Setting
or
Blocked
.
The control sources
Binary Input
and
Protocol
can continue to be operated,
even if they are not activated. However, the status Zx or Zx Stroke set in this way will
not take effect until the associated control source is selected again (see Figure 2-11).
For zone changeover by
Protocol
the commands 13811 through 13813 "Distance
Zone Zx Stroke ON" are provided.
With
Binary Input
the changeover of Z1, Z2 and Z3 is performed via the binary
input indications FNo. 3900 and 3901, 3902 and 3903, or 3906 and 3907, ">Dist. Zone
Zx stroke is active" and ">Dist.: Zone Zx is active".
The binary inputs also allow to switch the setting
CHANGE ZONE
to
Protocol
when
the binary input 365
„>Ctrl Select.“
= „>Select: Control by BI or SYS interface“ is
activated.
With the setting
Setting
the changeover is performed with the parameters
1302
Zone Sel. Z1
,
1342
Zone Sel. Z2
and
1362
Zone Sel. Z3
. These parameters
are masked out if a different control source is selected.
The figure below shows the logic of the zone changeover, with zone Z1 as an example.
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