GE G60 Instruction Manual

Also see for Multilin g60: Communications manual Communications guide Instruction manual Instruction manual Instruction manual

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GE Multilin G60 Generator Management Relay 5-1275 SETTINGS 5.5 GROUPED ELEMENTS5• NEG SEQ DIR OC1 OFFSET: This setting specifies the offset impedance used by this protection. The primary applica-tion for the offset impedance is to guarantee correct identification of fault direction on series compensated lines (seethe Application of Settings chapter for information on how to calculate this setting). In regular applications, the offsetimpedance ensures proper operation even if the negative-sequence voltage at the relaying point is very small. If this isthe intent, the offset impedance shall not be larger than the negative-sequence impedance of the protected circuit.Practically, it shall be several times smaller. The offset impedance shall be entered in secondary ohms. See the Theoryof Operation chapter for additional details.• NEG SEQ DIR OC1 TYPE: This setting selects the operating mode for the overcurrent unit of the element. Thechoices are “Neg Sequence” and “Zero Sequence”. In some applications it is advantageous to use a directional nega-tive-sequence overcurrent function instead of a directional zero-sequence overcurrent function as inter-circuit mutualeffects are minimized.• NEG SEQ DIR OC1 POS-SEQ RESTRAINT: This setting controls the amount of the positive-sequence restraint. Setto 0.063 (in “Zero Sequence” mode) or 0.125 (in “Neg Sequence” mode) for backward compatibility with firmware revi-sion 3.40 and older. Set to zero to remove the restraint. Set higher if large system unbalances or poor CT performanceare expected.• NEG SEQ DIR OC1 FWD ECA: This setting select the element characteristic angle (ECA) for the forward direction.The element characteristic angle in the reverse direction is the angle set for the forward direction shifted by 180°.• NEG SEQ DIR OC1 FWD LIMIT ANGLE: This setting defines a symmetrical (in both directions from the ECA) limitangle for the forward direction.• NEG SEQ DIR OC1 FWD PICKUP: This setting defines the pickup level for the overcurrent unit in the forward direc-tion. Upon NEG SEQ DIR OC1 TYPE selection, this pickup threshold applies to zero- or negative-sequence current. Whenselecting this setting it must be kept in mind that the design uses a ‘positive-sequence restraint’ technique.• NEG SEQ DIR OC1 REV LIMIT ANGLE: This setting defines a symmetrical (in both directions from the ECA) limitangle for the reverse direction.• NEG SEQ DIR OC1 REV PICKUP: This setting defines the pickup level for the overcurrent unit in the reverse direc-tion. Upon NEG SEQ DIR OC1 TYPE selection, this pickup threshold applies to zero- or negative-sequence current. Whenselecting this setting it must be kept in mind that the design uses a ‘positive-sequence restraint’ technique.Figure 5–70: NEGATIVE SEQUENCE DIRECTIONAL OC1 SCHEME LOGICFLEXLOGIC OPERANDFLEXLOGIC OPERANDSETTINGSETTINGSETTINGSETTINGSETTINGSSETTINGSETTINGNEG SEQ DIR OC1FUNCTION:NEG SEQ DIR OC1SOURCE:NEG SEQ DIR OC1TYPE:NEG SEQ DIR OC1 BLK:NEG SEQ DIR OC1 FWDLIMIT ANGLE:NEG SEQ DIR OC1 REVLIMIT ANGLE:NEG SEQ DIR OC1OFFSET:NEG SEQ DIR OC1 FWDECA:NEG SEQ DIR OC1 FWDPICKUP:NEG SEQ DIR OC1 REVPICKUP:NEG SEQ DIR OC1 FWDNEG SEQ DIR OC1 REVDisabled=0Neg Seq Seq Crt (I_2)Neg Seq Voltage (V_2)Neg SequenceZero Seq Seq Crt (I_0)Zero Sequence827091A4.CDROff=0Enabled=1ANDANDANDANDANDANDANDANDANDORORI I_2 - K _1 PICKUPI I_2 - K _1 PICKUPI I_0 - K _1 PICKUPI I_0 - K _1 PICKUPVoltage PolarizationV_2 polFWDFWDREVREV.RUNRUNRUNRUNRUN1.25 cy1.5 cyNEG SEQ DIR OC1 POS-SEQ RESTRAINT:NEG SEQ DIR OC1 POS-SEQ RESTRAINT: