GE N60 Instruction Manual page 277

5 SETTINGS
• 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
Figure 5–59: POWER SWING DETECT SCHEME LOGIC (1 of 3)
Figure 5–60: POWER SWING DETECT SCHEME LOGIC (2 of 3)
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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