Control Elements - GE D90 Plus Instruction Manual

CHAPTER 7: PROTECTION

Control elements

PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
where
m is a multiplier defined by the multiplier setting
S is the pickup setting
ref
S is the operating power at the time. This timer starts after the definite time timer
op
expires.
The four FlexCurves allow for custom user-programmable time characteristics. When
working with FlexCurves, the element uses the operate to pickup ratio, and the multiplier
setting is not applied:
Again, the FlexCurve timer starts after the definite time timer expires.
Multiplier
Range: 0.01 to 2.00 seconds in steps of 0.01
Default: 1.00 seconds
This setting is applicable if the wattmetric
multiplier factor for the inverse time delay.
Block
Range: any FlexLogic operand
Default: Off
Assertion of the FlexLogic operand assigned to this setting blocks operation of the
wattmetric zero-sequence directional ground fault element.
Events
Range: Enabled, Disabled
Default: Disabled
This setting enables and disables the logging of wattmetric zero-sequence directional
ground fault events in the sequence of events recorder.
The figure shows the logic for the wattmetric zero-sequence directional ground fault 1
element. The logic is identical for both wattmetric elements.
Figure 251: Wattmetric zero-sequence directional ground fault logic
Control elements generally are used for control rather than protection.
setting is "Inverse" and defines the
Curve
CONTROL ELEMENTS
Eq. 39
291