Oscillography - GE L30 Instruction Manual

PRODUCT SETUP
The
FAULT REPORT 1 SOURCE
application of entirely parallel lines, the fault report can be programmed to apply compensation for the zero sequence
mutual coupling between parallel lines when calculating fault resistance and fault loop impedance. If this compensation is
required, the ground current (3I_0) from the parallel line must be connected to the ground input CT of the CT bank
configured under the
source.
The
FAULT 1 REPORT TRIG
operational fault location calculations. The distance to fault calculations are initiated by this signal. The
,
MAG FAULT REPORT 1 Z0 MAG
For the application of entirely parallel lines, Z0M MAG/ANG is the mutual zero-sequence impedance for the whole line,
required to compensate the calculation of fault resistance and fault loop impedance.
The
FAULT REPORT 1 VT SUBSTITUTION
VTs are used, and the relay is supplied with the neutral (3V0) voltage, this setting is set to "V0". The method is still exact, as
the fault locator combines the line-to-line voltage measurements with the neutral voltage measurement to re-create the
line-to-ground voltages. See the
the delta and neutral voltages under the source indicated as input for the fault report. Also, the relay checks if the auxiliary
signal configured is marked as "Vn" by the user (under VT setup) and inhibits 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
FAULT REPORT 1 VT SUBSTITUTION
The
FAULT REP 1 SYSTEM Z0 MAG
value is "I0". The magnitude is to be entered in secondary ohms. This impedance is an average system equivalent behind
5
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 is trusted accordingly. Keep in mind that grounding points in the vicinity of the installation impact the system
zero-sequence impedance (grounded loads, reactors, zig-zag transformers, shunt capacitor banks, and so on).

5.3.8 Oscillography

5.3.8.1 Menu
SETTINGS  PRODUCT SETUP  OSCILLOGRAPHY
 OSCILLOGRAPHY

5-100
setting selects the source for input currents and voltages and disturbance detection. For the
with the same polarity as the phase current input configured in the same
FAULT REPORT 1 SOURCE
setting assigns the FlexLogic operand representing the protection element/elements requiring
, and
FAULT REPORT 1 Z0M MAG
setting is set to "None" if the relay is fed from wye-connected VTs. If delta-connected
ACTUAL VALUES  RECORDS  FAULT REPORTS
setting is set to "I0".
and
FAULT REP 1 SYSTEM Z0 ANGLE
NUMBER OF RECORDS:

15
TRIGGER MODE:

Automatic Overwrite
TRIGGER POSITION:

50%
TRIGGER SOURCE:

Off
AC INPUT WAVEFORMS:

16 samples/cycle
 DIGITAL CHANNELS


 ANALOG CHANNELS


impedances are entered in secondary ohms.
menu for details. It is required to configure
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
See below
See below
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
FAULT REPORT 1 Z1
setting
VT SUBSTITUTION