CHAPTER 7: PROTECTION
CONTROL ELEMENTS
D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
361
Figure 301: Overfrequency configuration settings
The following settings are available for each overfrequency element.
Function
Range: Enabled, Disabled
Default: Disabled
This setting enables and disables the overfrequency function.
Source
Range: LINE (SRC 1), BKR 1 (SRC 2), BKR 2 (SRC 3)
Default: LINE (SRC 1)
This setting selects the source for the signal to be measured.
Pickup
Range: 20.00 to 65.00 Hz in steps of 0.01
Default: 60.50 Hz
This setting specifies the level at which the overfrequency element is to pickup.
Pickup Delay
Range: 0.000 to 65.535 seconds in steps of 0.001
Default: 0.500 seconds
This setting specifies a time delay on pickup for the duration between the pickup and
operate output states of the overfrequency element.
Reset Delay
Range: 0.000 to 65.535 seconds in steps of 0.001
Default: 0.500 seconds
This setting specifies a time delay on dropout for the duration between the operate
output state and the return to logic 0 after the input transits outside the defined pickup
range.
Block
Range: any FlexLogic™ operand or shared operand
Default: OFF
Assertion of the operand assigned to this setting blocks operation of the overfrequency
element.
Events
Range: Enabled, Disabled
Default: Disabled
This setting enables and disables the logging of overfrequency events in the sequence of
events recorder.
The logic for the overfrequency function is shown below.
