Oscillography - GE C60 Instruction Manual

Breaker protection system
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PRODUCT SETUP
The trigger can be any FlexLogic operand, but in most applications it is expected to be the same operand, usually a virtual
output, that is used to drive an output relay to trip a breaker. To prevent the overwriting of fault events, do not use the
disturbance detector to trigger a fault report. A FAULT RPT TRIG event is automatically created when the report is triggered.
If a number of protection elements are ORed to create a fault report trigger, the first operation of any element causing the
OR gate output to become high triggers a fault report. However, If other elements operate during the fault and the first
operated element has not been reset (the OR gate output is still high), the fault report is not triggered again. Considering
the reset time of protection elements, there is very little chance that a fault report can be triggered twice in this manner. As
the fault report must capture a usable amount of pre and post-fault data, it cannot be triggered faster than every 20 ms.
Each fault report is stored as a file; the relay capacity is 15 files. A 16th trigger overwrites the oldest file.
Individual fault report features store their files in the same memory space. The sixteenth report overwrites the first one
regardless of which fault report feature produced the sixteenth and the first records.
The EnerVista software is required to view all captured data. The relay faceplate display can be used to view the date and
time of trigger, the fault type, the distance location of the fault, and the reclose shot number.
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,
5
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
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:
5
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
C60 BREAKER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
FAULT REPORT 1 Z1
setting
VT SUBSTITUTION

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