GE N60 Instruction Manual page 287

5 SETTINGS
• POWER SWING PICKUP DELAY 4: Controls the out-of-step tripping function in "Delayed" trip mode only. 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 charac-
teristic. This time delay is provided for extra security and should be set considering the fastest expected power swing.
• POWER SWING SEAL-IN DELAY: The out-of-step trip FlexLogic operand (
specified period of time. The sealing-in is crucial in the delayed trip mode, as the original trip signal is a very short
pulse occurring when the impedance locus leaves the outer characteristic after the out-of-step sequence is completed.
• POWER SWING TRIP MODE: Selection of the "Early" trip mode results in an instantaneous trip after the last step in
the out-of-step tripping sequence is completed. The early trip mode will stress the circuit breakers as the currents at
that moment are high (the electromotive forces of the two equivalent systems are approximately 180° apart). Selection
of the "Delayed" trip mode results in a trip at the moment when the impedance locus leaves the outer characteristic.
delayed trip mode will relax the operating conditions for the breakers as the currents at that moment are low. The
selection should be made considering the capability of the breakers in the system.
• POWER SWING BLK: This setting specifies the FlexLogic operand used for blocking the out-of-step function only. The
power swing blocking function is operational all the time as long as the element is enabled. The blocking signal resets
the output
POWER SWING TRIP
GE Multilin N60 Network Stability and Synchrophasor Measurement System
operand but does not stop the out-of-step tripping sequence.
5.6 GROUPED ELEMENTS
) is sealed-in for the
POWER SWING TRIP
5
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