GE D90 Plus Instruction Manual page 194

GROUPED PROTECTION ELEMENTS
184
overcurrent elements are used to identify a previously de-energized line that has been
closed onto a fault. Faults other than close-in faults can be identified satisfactorily with the
distance elements.
Co-ordination features are included to ensure satisfactory operation when high-speed
automatic reclosure is employed. Co-ordination is achieved by all of the line pickup
undervoltage elements resetting and blocking the trip path before the autoreclose co-
ordination delay times out.
The line pickup protection incorporates zone 1 extension capability. When the line is being
re-energized from the local terminal, pickup of an overreaching zone 2 or excessive phase
current within eight power cycles after the autorecloser issues a close command results in
the FlexLogic operand. For security, the overcurrent trip is supervised
LINE PICKUP RCL TRIP
by an undervoltage condition, which in turn is controlled by the
with a 10 ms coordination timer. Configure the
trip action if the intent is zone 1 extension.
The zone 1 extension philosophy used here normally operates from an under-reaching
zone, and it uses an overreaching distance zone when reclosing the line with the other line
end open. The
Autoreclose Accelerate
functionality if external autoreclosure is employed. Another zone 1 extension approach is
to apply permanently an overreaching zone, and reduce the reach when reclosing. This
philosophy can be programmed via the autoreclose scheme.
Select the Settings > Protection > Elements > Group 1 > Line Pickup menu to open the
line pickup configuration window. There is one line pickup element for each setting group.
Figure 163: Line pickup configuration window
The following settings are available.
Function
Range: Enabled, Disabled
Default: Disabled
This setting enables and disables the line pickup feature.
Signal Source
Range: LINE (SRC 1), BKR 1 (SRC 2), BKR 2 (SRC 3)
Default: LINE (SRC 1)
This setting selects the signal source for line pickup protection.
LINE PICKUP RCL TRIP
setting is provided to achieve zone 1 extension
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: PROTECTION
operand
VT FUSE FAIL OP
operand to perform a