ABB REL650 Product Manual

Also see for REL650 series: Technical manual Product guide Product guide Technical manual Commissioning manual

Contents

ABB REL650 Product Manual Manual pdf 18 page image

Normally the own breaker is tripped to correct such asituation. If the situation persists the surrounding breakersshould be tripped to clear the unsymmetrical load situation.The Pole discordance protection function (CCPDSC) operatesbased on information from auxiliary contacts of the circuitbreaker for the three phases with additional criteria fromunsymmetrical phase currents when required.Voltage-restrained time overcurrent protection VRPVOCGUID-935E1CE8-601F-40E2-8D22-2FF68420FADF v6Voltage-restrained time overcurrent protection (VRPVOC)function can be used as generator backup protection againstshort-circuits.The overcurrent protection feature has a settable current levelthat can be used either with definite time or inverse timecharacteristic. Additionally, it can be voltage controlled/restrained.One undervoltage step with definite time characteristic is alsoavailable within the function in order to provide functionalityfor overcurrent protection with undervoltage seal-in.5. Voltage protectionTwo-step undervoltage protection UV2PTUV M13789-3 v12Undervoltages can occur in the power system during faults orabnormal conditions. The two-step undervoltage protectionfunction (UV2PTUV) can be used to open circuit breakers toprepare for system restoration at power outages or as a long-time delayed back-up to the primary protection.UV2PTUV has two voltage steps, each with inverse or definitetime delay.It has a high reset ratio to allow settings close to the systemservice voltage.Two step overvoltage protection OV2PTOV M13798-3 v15Overvoltages may occur in the power system during abnormalconditions such as sudden power loss, tap changerregulating failures, and open line ends on long lines.Two step overvoltage protection (OV2PTOV) function can beused to detect open line ends, normally then combined with adirectional reactive over-power function to supervise thesystem voltage. When triggered, the function will cause analarm, switch in reactors, or switch out capacitor banks.OV2PTOV has two voltage steps, each of them with inverseor definite time delayed.OV2PTOV has a high reset ratio to allow settings close tosystem service voltage.Two step residual overvoltage protection ROV2PTOV M13808-3 v11Residual voltages may occur in the power system duringearth faults.Two step residual overvoltage protection (ROV2PTOV)function calculates the residual voltage from the three-phasevoltage input transformers or measures it from a singlevoltage input transformer fed from an open delta or neutralpoint voltage transformer.ROV2PTOV has two voltage steps, each with inverse ordefinite time delay.A reset delay ensures operation for intermittent earth faults.6. Frequency protectionUnderfrequency protection SAPTUF M13349-3 v13Underfrequency occurs as a result of a lack of generation inthe network.Underfrequency protection (SAPTUF) measures frequencywith high accuracy, and is used for load shedding systems,remedial action schemes, gas turbine startup and so on.Separate definite time delays are provided for operate andrestore.SAPTUF is 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.Overfrequency protection SAPTOF M14953-3 v12Overfrequency protection function (SAPTOF) is applicable inall situations, where reliable detection of high fundamentalpower system frequency is needed.Overfrequency occurs because of sudden load drops orshunt faults in the power network. Close to the generatingplant, generator governor problems can also cause overfrequency.SAPTOF measures frequency with high accuracy, and is usedmainly for generation shedding and remedial action schemes.It is also used as a frequency stage initiating load restoring. Adefinite time delay is provided for operate.SAPTOF 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.Rate-of-change of frequency protection SAPFRC M14965-3 v13The rate-of-change of frequency protection function(SAPFRC ) gives an early indication of a main disturbance inthe system. SAPFRC measures frequency with high accuracy,and can be used for generation shedding, load shedding andremedial action schemes. SAPFRC can discriminate betweena positive or negative change of frequency. A definite timedelay is provided for operate.1MRK 506 384-BEN ALine distance protection REL650 2.2Product version: 2.2.118 ABB