GE D90 Plus - Protection Flexelements

CHAPTER 7: PROTECTION PROTECTION FLEXLOGIC
D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL 409
Table 25: Non-volatile latch operation table
The figure shows the logic diagram for protection non-volatile latches.
Figure 352: Non-volatile latch logic
Protection FlexElements
A FlexElement is a universal comparator that can be used to monitor any analog actual
value calculated by the relay or a net difference between any two analog actual values of
the same type. The effective operating signal can be treated as a signed number or an
absolute value. The output from a FlexElement can also be used for further logic
processing. The number of FlexElements dedicated is 16.
The element can be programmed to respond either to a signal level or to a rate-of-change
(delta) over a pre-defined period of time. The output operand is asserted when the
operating signal is higher than a threshold or lower than a user-specified threshold.
Select the Settings > Protection > Protection FlexLogic > FlexElements menu to open the
protection FlexElements configuration window.
Type Latch operation
Set Reset On Off
Reset-dominant ON OFF ON OFF
OFF OFF Previous state Previous state
ON ON OFF ON
OFF ON OFF ON
Set-dominant ON OFF ON OFF
ON ON ON OFF
OFF OFF Previous state Previous state
OFF ON OFF ON
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