CHAPTER 7: PROTECTION
GROUPED PROTECTION ELEMENTS
D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
257
Function
Range: Enabled, Disabled
Default: Disabled
This setting enables and disables the negative-sequence instantaneous overcurrent
protection element.
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 negative-sequence instantaneous
overcurrent protection element.
Pickup
Range: 0.000 to 30.000 pu in steps of 0.001
Default: 1.000 pu
This setting specifies the negative-sequence instantaneous overcurrent pickup level in
per-unit values.
Delay
Range: 0.00 to 600.00 seconds in steps of 0.01
Default: 0.00 seconds
This setting delays the assertion of the
NEG SEQ IOC OP
operands. It is used to achieve
timing coordination with other elements and relays.
Reset Delay
Range: 0.00 to 600.00 seconds in steps of 0.01
Default: 0.00 seconds
This setting specifies a delay for the reset of the phase instantaneous overcurrent
element between the operate output state and the return to logic 0 after the input
passes outside the defined pickup range. This setting is used to ensure that the relay
output contacts are closed long enough to ensure reception by downstream equipment.
Block
Range: any FlexLogic™ operand or shared operand
Default: Off
Assertion of the operand assigned to this setting blocks operation of the negative-
sequence instantaneous overcurrent element.
Events
Range: Enabled, Disabled
Default: varies with UR
Plus
-series model; refer to the EnerVista UR
Plus
Setup software
This setting enables and disables the logging of negative-sequence instantaneous
overcurrent events in the sequence of events recorder.
The logic for the negative-sequence instantaneous overcurrent 1 element is shown below.
The logic is identical for all negative-sequence instantaneous overcurrent elements.
Figure 219: Negative-sequence instantaneous overcurrent scheme logic
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