GE D90 Plus Instruction Manual page 277

CHAPTER 7: PROTECTION
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
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 the phase undervoltage protection element.
Mode
Range: Phase to Ground, Phase to Phase
Default: Phase to Ground
This setting selects the operating mode. Select phase-to-ground or phase-to-phase for
wye VT connections, or phase-to-phase for delta VT connections.
Pickup
Range: 0.000 to 1.100 pu in steps of 0.001
Default: 1.000 pu
This setting specifies the phase undervoltage pickup level in per-unit values.
Curve
Range: Definite Time, Inverse Time
Default: Definite Time
This setting selects the required time-delay operating characteristic versus the applied
fundamental voltage or the definite time element.
Delay
Range: 0.00 to 600.00 seconds in steps of 0.01
Default: 1.00 seconds
This setting specifies the minimum operating time of the phase undervoltage element.
Minimum Voltage
Range: 0.000 to 3.000 pu in steps of 0.001
Default: 0.100 pu
This setting specifies the operating voltage in per-unit values below which the element is
blocked. A value of "0" allows a dead source to be considered a fault condition.
Block
Range: any FlexLogic operand or shared operand
Default: Off
Assertion of the operand assigned to this setting blocks the phase undervoltage
element.
Events
Range: Enabled, Disabled
Default: Disabled
This setting enables and disables the logging of phase undervoltage events in the
sequence of events recorder.
The following protection FlexLogic operands are available for the phase undervoltage
elements.
Phase undervoltage operands
PHASE UV1 DPO .........................................Asserted when at least one phase of the phase undervoltage 1
PHASE UV1 DPO A .....................................Asserted when phase A of the phase undervoltage 1 element
PHASE UV1 DPO B .....................................Asserted when phase B of the phase undervoltage 1 element
PHASE UV1 DPO C .....................................Asserted when phase C of the phase undervoltage 1 element
element drops out.
drops out.
drops out.
drops out.
GROUPED PROTECTION ELEMENTS
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