网络互动营销的几个关键点课件.ppt

IEEE C37.234 Guide for Protective Relay Application to Power System Buses,B.Kasztenny (Chairman), S.Conrad (Vice-Chairman), P.Beaumont, K.Behrendt, O.Bolado, J.Boyle, G.Brunello, J.Burger, F.Calero, S.Chano, G.Dalke, A.Darlington, H.DoCarmo, D.Fontana, Z.Gajic, J.Holbach, L.Kojovic, F.Lopez, D.Lukach, D.McGinn, J.Miller, P.Mysore, J.OBrien, B.Pickett, S.Sambasivan, G.Sessler, V.Skendzic, J.Smith, D.Tholomier, M.Thompson, J.Uchiyama, D.Ware, D.Weers, R.Whittaker, R.Young, S.Zocholl,Presentation to the Main Committee of PSRC, January 14, 2010, Orlando, FL,迈鼎 http:/,Table of Contents,DefinitionsBus configurationsIntroduction to bus protectionRelay input sourcesBus protection methodsApplication of bus protection schemesAnnexes,Definitions,23 new terms definedBus protection and primary equipment,breaker substitution Temporary usage of a bus tie breaker in a multiple bus configuration to substitute for one of the network elements circuit breakers, typically for the maintenance of the latter; also known as breaker transfer,check zone Nonselective part of a multi-zone bus protection system measuring current flows around the entire station and supervising selective tripping from individual bus zones of protection,stub bus Area of a bus or line that becomes isolated from the original zone of protection or an area that loses protection due to the loss of sensing to zone protection relays,Bus design considerations,Continuity of service for the bus and essential network elementsEquipment maintainability and network switching flexibilityEconomical and footprint constraintsSectionalizing requirements to avoid exceeding breaker fault dutiesEase of future bus expansion,Bus arrangements,Single busMain and transfer busDouble-bus double-breakerDouble-bus single-breakerBreaker-and-a-halfRing bus,Main and transfer bus,Main and transfer bus,Introduction to bus protection,Zones of protectionBus protection methodsScheme selection guidelines,Zones of protection,Dynamic zones of protection,Dynamic zones of protection,Dynamic zones of protection,Zones of protection,Bus protection methods,DifferentialDifferentially-connected overcurrentInstantaneousTime-delayedPercentage-restrained differentialRestrainedAdvanced microprocessor basedHigh-impedance differentialResistor-stabilized overcurrentHigh-impedancePartial differential overcurrentFault bus,Bus protection methods,Zone-interlocked schemesSimple blockingDirectional blockingTime-coordinated relays overlapping the busProtection (sensors) built into the gas isolated switchgear*,* Not covered in the Guide,Scheme selection criteria,Bus arrangement and flexibilityFixed vs. switchable busesAvailability and characteristics of CTsFor reconfigurable buses, availability of auxiliary contacts of disconnect switchesPerformance requirementsSecurity, Selectivity, Speed, SensitivityCost and complexity,Scheme selection,Relay input sources,Current transformersTypesAccuracy classesEquivalent circuit & time to saturationNo universal CT requirementsVoltage TransformersVoltage trip supervisionDirectional blocking schemesPosition of switches and breakers,Detailed scheme review,Section 7 gives in-depth review of each method following a consistent patternTheory of operationSetting considerationsCT requirementsApplication considerations,Example High-impedance scheme,Voltage setting:Above the maximum voltage for an external fault assuming that one CT saturates completely High enough so that pickup current is above the short circuit current on the secondary of any PT or station service transformer inside the bus zoneBelow the accuracy class voltage rating of the lowest accuracy class CT in the differential circuit Low enough so that pickup current is below the minimum fault current for the bus,Example High-impedance scheme,CT requirements:CTs dedicated to bus protection (cannot be shared)Equal CT ratios*The accuracy class voltage rating of the CT with the lowest accuracy class above the selected voltage setting, with margin,* Ratio matching covered but discouraged,Application of bus protection,Partial differentialLoadsCapacitor banksApplication with overcurrent and distance relaysCombined bus and transformer zoneBuses with directly connected grounding transformersApplication of auxiliary transformersGenerally discouraged,Application of bus protection,Applications with paralleled CTsGenerally discouragedGuidelines included,Application of bus protection,Application of auxiliary tripping relaysLockout relaysNon-lockout relaysRatings Automatic reclosing after bus faultsDynamic bus replicaCheck-zoneVoltage trip supervision,Dynamic bus replica,Position of switches and breakers,“If not opened, then closed” logic,In-service transfer,In-service transfer,In-service transfer,Check zone,Application of bus protection,Application of CT trouble detectionDetection methodsFallback strategiesReliable, selective tripping at the differential zone boundaryLine-side CTBus-side CTBus coupler considerationsThe role of Breaker Failure protection,Line-side CT,Bus coupler considerations,Bus coupler considerations,Application of bus protection,CT column ground fault protectionIn-zone groundsSurge arrestersSafety grounds and circulating current while testingIn-zone grounding of out-of-service elementsIn-service transfer of network elements and breaker substitution,Breaker substitution,Application of bus protection,Stub bus considerationsBreaker Failure considerationsBackup protectionLocal backupDuplicated relaysBF, batteries, wiringReverse-looking distance relaysOvercurrent relaysRemote backup,Annexes,Setting example for a high-impedance scheme (Annex A)Logic example for double-bus single-breaker configuration (Annex B)Bus and Breaker Failure protectionTwo zones, check zone and voltage supervisionIn-service transfers and breaker substitutionSetting guidelines for differentially connected OC schemes (Annex C),C37.234 Highlights,Complex bus arrangements and switchingAdvanced bus protection topics (reconfigurable buses, mP relays)Balanced coverage of high- and low-impedance schemesProtection scheme selection guidelinesCT requirements given per schemeList of application considerationsDetailed examples for most common schemes,