ABB RED670 Product Manual
Also see for RED670 Relion 670 series: Installation manualInstallation manualCommissioning manualProduct guideTechnical reference manual
                                                                                                                      | |
Two step overvoltage protection (OV2PTOV, 59) function canbe used to detect open line ends, normally then combined witha directional reactive over-power function to supervise thesystem voltage. When triggered, the function will cause analarm, switch in reactors, or switch out capacitor banks.OV2PTOV (59) has two voltage steps, each of them with inverseor definite time delayed.OV2PTOV (59) has an extremely high reset ratio to allowsettings close to system service voltage.Two step residual overvoltage protection ROV2PTOV (59N)Residual voltages may occur in the power system duringground faults.Two step residual overvoltage protection ROV2PTOV (59N)function calculates the residual voltage from the three-phasevoltage input transformers or measures it from a single voltageinput transformer fed from a broken delta or neutral pointvoltage transformer.ROV2PTOV (59N) has two voltage steps, each with inverse ordefinite time delay.Reset delay ensures operation for intermittent ground faults.Overexcitation protection OEXPVPH (24)When the laminated core of a power transformer or generator issubjected to a magnetic flux density beyond its design limits,stray flux will flow into non-laminated components not designedto carry flux and cause eddy currents to flow. The eddycurrents can cause excessive heating and severe damage toinsulation and adjacent parts in a relatively short time. Thefunction has settable inverse operating curves and independentalarm stages.Voltage differential protection VDCPTOV (60)A voltage differential monitoring function is available. Itcompares the voltages from two three phase sets of voltagetransformers and has one sensitive alarm step and one trip step.Loss of voltage check LOVPTUV (27)Loss of voltage check (LOVPTUV, 27) is suitable for use innetworks with an automatic system restoration function.LOVPTUV (27) issues a three-pole trip command to the circuitbreaker, if all three phase voltages fall below the set value for atime longer than the set time and the circuit breaker remainsclosed.7. Frequency protectionUnderfrequency protection SAPTUF (81)Underfrequency occurs as a result of a lack of generation in thenetwork.Underfrequency protection SAPTUF (81) is used for loadshedding systems, remedial action schemes, gas turbinestartup and so on.SAPTUF (81) is also provided with undervoltage blocking.The operation is based on positive sequence voltagemeasurement and requires two phase-phase or three phase-neutral voltages to be connected. For information about how toconnect analog inputs, refer to Application manual/IEDapplication/Analog inputs/Setting guidelinesOverfrequency protection SAPTOF (81)Overfrequency protection function SAPTOF (81) is applicable inall situations, where reliable detection of high fundamentalpower system frequency is needed.Overfrequency occurs because of sudden load drops or shuntfaults in the power network. Close to the generating plant,generator governor problems can also cause over frequency.SAPTOF (81) is used mainly for generation shedding andremedial action schemes. It is also used as a frequency stageinitiating load restoring.SAPTOF (81) is provided with an undervoltage blocking.The operation is based on positive sequence voltagemeasurement and requires two phase-phase or three phase-neutral voltages to be connected. For information about how toconnect analog inputs, refer to Application manual/IEDapplication/Analog inputs/Setting guidelinesRate-of-change frequency protection SAPFRC (81)Rate-of-change frequency protection function (SAPFRC,81)gives an early indication of a main disturbance in the system.SAPFRC (81) can be used for generation shedding, loadshedding and remedial action schemes. SAPFRC (81) candiscriminate between positive or negative change of frequency.SAPFRC (81) is provided with an undervoltage blocking. Theoperation is based on positive sequence voltage measurementand requires two phase-phase or three phase-neutral voltagesto be connected. For information about how to connect analoginputs, refer to Application manual/IED application/Analoginputs/Setting guidelines.8. Multipurpose protectionGeneral current and voltage protection CVGAPCThe General current and voltage protection (CVGAPC) can beutilized as a negative sequence current protection detectingunsymmetrical conditions such as open phase or unsymmetricalfaults.Line differential protection RED670 ANSI 1MRK505226-BUS DCustomizedProduct version: 1.2ABB 21 |
Related manuals for ABB RED670 Relion 670 series
This manual is suitable for:
manualsdatabase
Your AI-powered manual search engine