GE D90 Plus Instruction Manual page 228

GROUPED PROTECTION ELEMENTS
218
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 need to be set to detect the
fastest expected power swing and produce out-of-step tripping in a secure manner. Set
the timers in relation 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 specifies 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,
Pickup
is started. When the timer times-out, the latch is reset. Select this setting 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
specifies 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
This setting controls the out-of-step tripping function in the "Delayed" trip mode. This
timer specifies 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. Set it considering the fastest
expected power swing.
setting. This time delay is provided for
Trip Mode
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: PROTECTION
Delay 1
Delay 1 Reset