Oscillography - GE L90 Instruction Manual

5.2 PRODUCT SETUP
For a two-terminal line application, the
and
REPORT 1 Z0 ANG
For a three-terminal application, these settings are used to enter the line segment impedance and length from the local ter-
minal to the tap point only.
The
FAULT REP 1 REM1-TAP Z1 MAG
enter positive sequence section impedances (in secondary ohms) for the line segment from remote terminal 1 to the tap
point. The length of the line section from remote terminal 1 to the tap point is entered in the
setting.
The
FAULT REP 1 REM2-TAP Z1 MAG
above, but for the line segment from remote terminal 2 to the tap point.
The
FAULT REPORT 1 VT SUBSTITUTION
nected VTs are used, and the relay is supplied with the neutral (3V0) voltage, this setting shall be set to "V0". The method is
still exact, as the fault locator would combine the line-to-line voltage measurements with the neutral voltage measurement
to re-create the line-to-ground voltages. See the
details. It required to configure the delta and neutral voltages under the source indicated as input for the fault report. Also,
the relay will check if the auxiliary signal configured is marked as "Vn" by the user (under VT setup), and inhibit the fault
location if the auxiliary signal is labeled differently.
If the broken-delta neutral voltage is not available to the relay, an approximation is possible by assuming the missing zero-
sequence voltage to be an inverted voltage drop produced by the zero-sequence current and the user-specified equivalent
zero-sequence system impedance behind the relay: V0 = –Z0 × I0. In order to enable this mode of operation, the
REPORT 1 VT SUBSTITUTION
The
FAULT REP 1 SYSTEM Z0 MAG
ting value is "I0". The magnitude is to be entered in secondary ohms. This impedance is an average system equivalent
5
behind the relay. It can be calculated as zero-sequence Thevenin impedance at the local bus with the protected line/feeder
disconnected. The method is accurate only if this setting matches perfectly the actual system impedance during the fault. If
the system exhibits too much variability, this approach is questionable and the fault location results for single-line-to-ground
faults shall be trusted with accordingly. It should be kept in mind that grounding points in vicinity of the installation impact
the system zero-sequence impedance (grounded loads, reactors, zig-zag transformers, shunt capacitor banks, etc.).
For proper operation of the multi-ended fault locator, the nominal primary voltage is expected to appear identical at
all line terminals as seen from the nominal secondary voltage, VT ratio, and VT connection settings of the first 87L
NOTE
source.
a) MAIN MENU
PATH: SETTINGS PRODUCT SETUP

OSCILLOGRAPHY

5-38
FAULT REPORT 1 Z1 MAG
settings for the entire line must to be entered for fault location calculations.
FAULT REPORT 1 LENGTH
and
FAULT REP 1 REM1-TAP Z1 ANG
,
FAULT REP 1 REM2-TAP Z1 ANG
setting shall be set to "None" if the relay is fed from wye-connected VTs. If delta-con-
ACTUAL VALUES
setting shall be set to "I0".
and
FAULT REP 1 SYSTEM Z0 ANGLE
OSCILLOGRAPHY
NUMBER OF RECORDS:
5
TRIGGER MODE:
MESSAGE
Automatic Overwrite
TRIGGER POSITION:
MESSAGE
50%
TRIGGER SOURCE:
MESSAGE
Off
AC INPUT WAVEFORMS:
MESSAGE
16 samples/cycle
DIGITAL CHANNELS
MESSAGE
ANALOG CHANNELS
MESSAGE
L90 Line Current Differential System
, ,
FAULT REPORT 1 Z1 ANG FAULT REPORT 1 Z0 MAG
settings are used for three-terminal applications to
FAULT REP 1 REM1-TAP LENGTH
, and
FAULT REP 1 REM2-TAP LENGTH
RECORDS FAULT REPORTS
settings are used only when the
Range: 1 to 64 in steps of 1
Range: Automatic Overwrite, Protected
Range: 0 to 100% in steps of 1
Range: FlexLogic™ operand
Range: Off; 8, 16, 32, 64 samples/cycle
5 SETTINGS
,
FAULT
settings are used as
menu for additional
FAULT
set-
VT SUBSTITUTION
5.2.8 OSCILLOGRAPHY
GE Multilin