搜索
外文资料APPLICATIONOFTHETHEORYOFPATTERNRECOGNITIONINDEVELOPINGRELAYPROTECTIONANDCONTROLV.E.GLazyrinNovosibirskStateTechnicalUniversityReliableandtimelyrecognitionofemergencystatesinelectricalsystemsrequiressolutionsthatareadequateforthetechnicalequipmentbeingused.Formorethantenyearsdiscretecomputingdeviceshavebeenwidelyimplementedinrelayprotectionandcontrol.Theappearanceofmicroprocessorshasgivendevelopersextremelypowerfultoolsforusingnewprinciplesandalgorithmsindesigningrelaysystems.Despitethis,thedesignstrategyremainspracticallyunchanged,thoughthenewelementbaseexceedsthecapabilitiesoftheconventionalonetothedegreethatitissimplyonaqualitativelyhigherlevel.Inconnectionwiththis,thenecessityhasripenedforqualitativelynewapproachestodesigningrelaysystems.Conventionaldesignmethodsverymuchdependontheintuitionandexperienceofthedeveloper.Theexecutionoftheworkisfrequentlyunpredictable,sincethedevelopermustsimultaneouslyrepresentthestateofmany(sometimesmorethanten)parameters.Atthesametime,apersonhasalimitedcapacitytosimultaneouslykeepinmindmanyobjects.Thiscausesnotonlycomplexityindevelopingnewdevices,butalsocausesthesubjectivephenomenonofagroupofrelayprotectionexpertswhichhaveonanintuitivelevelmasteredacombinationaseveralgroupsofconcepts.Thisreducesthenumberofobjectswhichmustbekeptinmindsimultaneously,buttheformationofthesecombinedgroupshasnotbeenformalized,whichhindersmutualunderstanding.Duringthedevelopmentofnewcomplexdevicesofrelaysystems,thequantityofparameters,withwhichthedeveloperhastoworksimultaneouslyincreasesevenmore.Thisnotonlycomplicatesthedesign,butalsoincreasestheprobabilityoferrors,whichsimultaneouslyhindersthecontroloftheaccuracyoftheexecutionofactivitiesforcreatingalgorithms,designingdevices,writingprogramsandconductingcorrectiontests.Intheconventionaldesignapproach,asuccessiveanalysisofsignalsismadeanddecisionsaremadeastheyarereceived.Insodoingtheevaluationofthecurrentstateoftheexaminedobjectiscarriedoutbythesuccessiveanalysisoftransitionsofmeasuringfromoneconditiontoanother.Thisapproachtodevelopingalgorithmshasalsobecomeaconstrainingfactorindevelopingeffectivealgorithms.Asanexample,weshallconsideroneofthecomplexrelaysystemdevices,detectorsofasynchronousoperation.Themostdevelopedarethosedetectorshavingremoteunitsandunitsfordirectionofpower.Anasynchronousmodeisrecognizedbyanalyzingthesequenceoftransitionsofthemeasuredresistancevaluewhichisdefinedbytherelationshipwiththevoltageandcurrentinputtedintothemeasuringunits.Duringtheoperationoftheobject,theendofthevectorZ,canmoverelativetotheoperatingrangesoftheunitsdependingonthecharacteroftheoperationalmode.Thestandarddeviceconsistsofthreerelayassemblyofresistance,havingvariouscharacteristicsofswitching,ofmaximumrelayassemblyofpowerandofcounterofcyclesofasynchronousoperation.Inaddition,itcontainsaunitfordeterminingthesignoftheslip,circuitsforregisteringtheasynchronousmodeinthefirstcycle,circuitsforcontrollingtheperiodofasynchronousoperation,aunitforadditionaltime.grading,unitforresettingthedevice,andalsocircuitsforregisteringafaultinthedevice,thesignalingsystem,andtheoutputcircuits.Thedeviceconsistsofthreestages,eachofwhichhasoutputcircuit.Thefirststageisintendedforthefastestdetection(inthefirstcycle)ofanasynchronousmodeinthecontrolledsectionandthesignoftheslip.Thesecondstageisintendedforthedetectionofanasynchronousmodeinthecontrolledsectionandthesignoftheslipattheendofthesecond,thirdorfourthcycles.Thethirdstageisintendedforliquidationoftheasynchronousmodeafterexecutingmeasuresforresynchronization,ifduringtheadditionaltimelagaspecificquantityofcyclesoftheasynchronousmodeareregistered.Besidesthat,inordertomakesurethedevicedoesnotoperateduringshort-circuitsaunitofreversesequenceforblockingthedeviceinasymmetricalmodesisadvisable.Thus,itisclear,thatthedevicecontainsagreatnumberofunitsworkingjointly.Itshouldalsoworkinvariouswaysdependingnotonlyonthecombinationofthestatesofitsunits,butalsoontherelationshipbetweenthetimesthatinputunitsarefoundinvariousstates.Thatmeansthatthebehaviorofthedeviceshoulddependonacombinationofthestatesofalargenumberofoperationalunits,andthetimerelationshipsofappearanceanddisappearanceofsignalsfromvariousunitsalsomustbetakenintoconsideration.Thedescriptionofthelogicoftheoperationofsuchadeviceconstructedusingaconventionalelementbaseisadducedinandtakesmorethan20pages.Thedeviceitselfismadeintheformofastandardrelaypanel.Attemptstomakeaformaldescriptionofthelogicofthedevice'soperation,whichwouldbeconvenienttousetocreateaneffectiveprogramforamicroprocessor,haveturnedouttobeverylabor-consumingandhavenotgivenareliableoutcome.Toovercomethisdifficultyaspecialmathematicalapparatushasbeenappliedthathasreceivedthetitletheoryofapatternrecognition.Ithasbroadapplicationinotherareasofscienceandengineering,suchasradio-location,echo-location,processingtheoutcomesofairphotographyforagriculturalneeds,andalsofortechnicaldiagnostics.Applyingthemethodofpatternrecognitionassumesparallelinformationprocessing.Theprototypeforsuchprocessingishumanperception,whichtakestheen