GE D90 Plus Instruction Manual page 190

GROUPED PROTECTION ELEMENTS
182
Delay 1 Pickup
Range: 0.000 to 65.535 seconds in steps of 0.001
Default: 0.030 seconds
All the coordinating timers are related to each other and should be set to detect the
fastest expected power swing and produce out-of-step tripping in a secure manner. The
timers should be set in consideration to the power swing detect characteristics, mode of
power swing detect operation and mode of out-of-step tripping. This timer defines the
interval that the impedance locus must spend between the outer and inner
characteristics (two-step operating mode), or between the outer and middle
characteristics (three-step operating mode) before the power swing blocking signal is
established. This time delay must be set shorter than the time required for the
impedance locus to travel between the two selected characteristics during the fastest
expected power swing. This setting is relevant for both power swing blocking and out-of-
step tripping.
Delay 1 Reset
Range: 0.000 to 65.535 seconds in steps of 0.001
Default: 0.050 seconds
This setting defines the dropout delay for the power swing blocking signal. Detection of a
condition requiring a block output sets latch 1 after the time specified in the
setting. When the impedance locus leaves the outer characteristic, the timer
Pickup
specified by this setting is started. When the timer times-out the latch is reset. This
setting should be selected to give extra security for the power swing blocking action.
Delay 2 Pickup
Range: 0.000 to 65.535 seconds in steps of 0.001
Default: 0.017 seconds
This setting controls the out-of-step tripping function in the three-step mode. This timer
defines the interval the impedance locus must spend between the middle and inner
characteristics before the second step of the out-of-step tripping sequence is
completed. This time delay must be set shorter than the time required for the impedance
locus to travel between the two characteristics during the fastest expected power
swing.
Delay 3 Pickup
Range: 0.000 to 65.535 seconds in steps of 0.001
Default: 0.009 seconds
This setting controls the out-of-step tripping function only. It defines the interval the
impedance locus must spend within the inner characteristic before the last step of the
out-of-step tripping sequence is completed and the element is armed to trip. The actual
moment of tripping is controlled by the
extra security before the out-of-step trip action is executed.
Delay 4 Pickup
Range: 0.000 to 65.535 seconds in steps of 0.001
Default: 0.017 seconds
Controls the out-of-step tripping function in the delayed trip mode. This timer defines the
interval the impedance locus must spend outside the inner characteristic but within the
outer characteristic before the element is armed for the delayed trip. The delayed trip
occurs when the impedance leaves the outer characteristic. This time delay is provided
for extra security and should be set considering the fastest expected power swing.
Trip Mode setting. This time delay is provided for
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: PROTECTION
Delay 1