5-124 L60 Line Phase Comparison Relay GE Multilin5.5 GROUPED ELEMENTS 5 SETTINGS5The power swing detect element provides both power swing blocking and out-of-step tripping functions. The element mea-sures the positive-sequence apparent impedance and traces its locus with respect to either two or three user-selectableoperating characteristic boundaries. Upon detecting appropriate timing relations, the blocking and/or tripping indication isgiven through FlexLogic™ operands. The element incorporates an adaptive disturbance detector. This function does nottrigger on power swings, but is capable of detecting faster disturbances – faults in particular – that may occur during powerswings. Operation of this dedicated disturbance detector is signaled via the POWER SWING 50DD operand.The power swing detect element asserts two outputs intended for blocking selected protection elements on power swings:POWER SWING BLOCK is a traditional signal that is safely asserted for the entire duration of the power swing, and POWERSWING UN/BLOCK is established in the same way, but resets when an extra disturbance is detected during the power swing.The POWER SWING UN/BLOCK operand may be used for blocking selected protection elements if the intent is to respond tofaults during power swing conditions.Different protection elements respond differently to power swings. If tripping is required for faults during power swing condi-tions, some elements may be blocked permanently (using the POWER SWING BLOCK operand), and others may be blockedand dynamically unblocked upon fault detection (using the POWER SWING UN/BLOCK operand).The operating characteristic and logic figures should be viewed along with the following discussion to develop an under-standing of the operation of the element.The power swing detect element operates in three-step or two-step mode:• Three-step operation: The power swing blocking sequence essentially times the passage of the locus of the positive-sequence impedance between the outer and the middle characteristic boundaries. If the locus enters the outer charac-teristic (indicated by the POWER SWING OUTER FlexLogic™ operand) but stays outside the middle characteristic (indi-cated by the POWER SWING MIDDLE FlexLogic™ operand) for an interval longer than POWER SWING PICKUP DELAY 1,the power swing blocking signal ( POWER SWING BLOCK FlexLogic™ operand) is established and sealed-in. The block-ing signal resets when the locus leaves the outer characteristic, but not sooner than the POWER SWING RESET DELAY 1time.• Two-step operation: If the 2-step mode is selected, the sequence is identical, but it is the outer and inner characteris-tics that are used to time the power swing locus.MESSAGE POWER SWING INNERLFT BLD: 100.00 ΩRange: 0.10 to 500.00Ω in steps of 0.01MESSAGE POWER SWING PICKUPDELAY 1: 0.030 sRange: 0.000 to 65.535 s in steps of 0.001MESSAGE POWER SWING RESETDELAY 1: 0.050 sRange: 0.000 to 65.535 s in steps of 0.001MESSAGE POWER SWING PICKUPDELAY 2: 0.017 sRange: 0.000 to 65.535 s in steps of 0.001MESSAGE POWER SWING PICKUPDELAY 3: 0.009 sRange: 0.000 to 65.535 s in steps of 0.001MESSAGE POWER SWING PICKUPDELAY 4: 0.017 sRange: 0.000 to 65.535 s in steps of 0.001MESSAGE POWER SWING SEAL-INDELAY: 0.400 sRange: 0.000 to 65.535 s in steps of 0.001MESSAGE POWER SWING TRIPMODE: DelayedRange: Early, DelayedMESSAGE POWER SWING BLK:OffRange: Flexlogic™ operandMESSAGE POWER SWINGTARGET: Self-ResetRange: Self-Reset, Latched, DisabledMESSAGE POWER SWINGEVENTS: DisabledRange: Disabled, Enabled
