GE D30 series Instruction Manual

Also see for D30 series: Communications manual Communications guide Instruction manual Instruction manual Instruction manual

Contents

5-142 D30 Line Distance Protection System GE Multilin5.6 GROUPED ELEMENTS 5 SETTINGS5• POWER SWING QUAD REV REACH OUT: This setting specifies the reverse reach of the outer quadrilateral charac-teristic. The angle of this reach impedance is specified by the POWER SWING FWD RCA setting. The setting is not used ifthe shape setting is “Mho”.• POWER SWING REV RCA: This setting specifies the angle of the reverse reach impedance for the mho characteris-tics. This setting applies to mho shapes only.• POWER SWING OUTER LIMIT ANGLE: This setting defines the outer power swing characteristic. The conventiondepicted in the Power swing detect characteristic diagram should be observed: values greater than 90° result in anapple-shaped characteristic; values less than 90° result in a lens shaped characteristic. This angle must be selected inconsideration of the maximum expected load. If the maximum load angle is known, the outer limit angle should becoordinated with a 20° security margin. Detailed studies may be needed for complex systems to determine this setting.This setting applies to mho shapes only.• POWER SWING MIDDLE LIMIT ANGLE: This setting defines the middle power swing detect characteristic. It is rele-vant only for the 3-step mode. A typical value would be close to the average of the outer and inner limit angles. Thissetting applies to mho shapes only.• POWER SWING INNER LIMIT ANGLE: This setting defines the inner power swing detect characteristic. The innercharacteristic is used by the out-of-step tripping function: beyond the inner characteristic out-of-step trip action is defi-nite (the actual trip may be delayed as per the TRIP MODE setting). Therefore, this angle must be selected in consider-ation to the power swing angle beyond which the system becomes unstable and cannot recover.The inner characteristic is also used by the power swing blocking function in the two-step mode. In this case, set thisangle large enough so that the characteristics of the distance elements are safely enclosed by the inner characteristic.This setting applies to mho shapes only.• POWER SWING OUTER, MIDDLE, and INNER RGT BLD: These settings specify the resistive reach of the rightblinder. The blinder applies to both “Mho” and “Quad” characteristics. Set these value high if no blinder is required forthe “Mho” characteristic.• POWER SWING OUTER, MIDDLE, and INNER LFT BLD: These settings specify the resistive reach of the left blinder.Enter a positive value; the relay automatically uses a negative value. The blinder applies to both “Mho” and “Quad”characteristics. Set this value high if no blinder is required for the “Mho” characteristic.• POWER SWING PICKUP DELAY 1: All the coordinating timers are related to each other and should be set to detectthe fastest expected power swing and produce out-of-step tripping in a secure manner. The timers should be set inconsideration 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 charac-teristics (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 forthe impedance locus to travel between the two selected characteristics during the fastest expected power swing. Thissetting is relevant for both power swing blocking and out-of-step tripping.• POWER SWING RESET DELAY 1: This setting defines the dropout delay for the power swing blocking signal. Detec-tion of a condition requiring a block output sets latch 1 after PICKUP DELAY 1 time. When the impedance locus leavesthe outer characteristic, timer POWER SWING RESET DELAY 1 is started. When the timer times-out the latch is reset. Thissetting should be selected to give extra security for the power swing blocking action.• POWER SWING PICKUP DELAY 2: Controls the out-of-step tripping function in the three-step mode only. This timerdefines the interval the impedance locus must spend between the middle and inner characteristics before the secondstep of the out-of-step tripping sequence is completed. This time delay must be set shorter than the time required forthe impedance locus to travel between the two characteristics during the fastest expected power swing.• POWER SWING PICKUP DELAY 3: Controls the out-of-step tripping function only. It defines the interval the imped-ance locus must spend within the inner characteristic before the last step of the out-of-step tripping sequence is com-pleted and the element is armed to trip. The actual moment of tripping is controlled by the TRIP MODE setting. This timedelay is provided for extra security before the out-of-step trip action is executed.• POWER SWING PICKUP DELAY 4: Controls the out-of-step tripping function in “Delayed” trip mode only. This timerdefines the interval the impedance locus must spend outside the inner characteristic but within the outer characteristicbefore 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.