电气工程、自动化专业应聘笔试题（electrical engineering and automation professional candidates written examination questions）

电气工程、自动化专业应聘笔试题（ELECTRICALENGINEERINGANDAUTOMATIONPROFESSIONALCANDIDATESWRITTENEXAMINATIONQUESTIONS）THEELECTRICPOWERINDUSTRYOFELECTRICALENGINEERINGANDAUTOMATIONPROFESSIONALCANDIDATESMUSTKNOWINTERPRETATIONOFNOUNINTERPRETATIONNOUNINTERPRETATION1,THREEPHASEALTERNATINGCURRENTTHEPOWERSYSTEMCOMPOSEDOFTHREEACCIRCUITSWITHTHESAMEFREQUENCY,THESAMEAMPLITUDEOFELECTRICPOTENTIALANDTHEPHASEDIFFERENCEOF120DEGREESANGLEISCALLEDTHREEPHASEALTERNATINGCURRENT2,PRIMARYEQUIPMENTEQUIPMENTDIRECTLYRELATEDTOTHEPRODUCTIONOFELECTRICALENERGYANDPOWERTRANSMISSIONANDDISTRIBUTIONISCALLEDAPRIMARYEQUIPMENTINCLUDINGAVARIETYOFHIGHVOLTAGECIRCUITBREAKER,ISOLATEDPOWERINDUSTRYELECTRICALENGINEERINGANDAUTOMATIONPROFESSIONALCANDIDATESMUSTKNOWAGLOSSARYGLOSSARYGLOSSARY1,THETHREEPHASEACPOWERSYSTEMTHREEBYTHESAMEFREQUENCYANDAMPLITUDE,THEPHASEDIFFERENCEISEQUALTOTHEPOTENTIALDIFFERENCEBETWEENACCIRCUITCOMPOSEDOF120DEGREES,CALLEDTHREEPHASEALTERNATINGCURRENT2,PRIMARYEQUIPMENTEQUIPMENTDIRECTLYRELATEDTOTHEPRODUCTIONOFELECTRICALENERGYANDPOWERTRANSMISSIONANDDISTRIBUTIONISCALLEDAPRIMARYEQUIPMENTITINCLUDESALLKINDSOFHIGHVOLTAGECIRCUITBREAKER,DISCONNECTINGSWITCH,BUS,POWERCABLE,VOLTAGETRANSFORMER,CURRENTTRANSFORMER,REACTOR,LIGHTNINGARRESTER,ARCSUPPRESSIONCOIL,SHUNTCAPACITORANDHIGHVOLTAGEFUSE3ANDTWOEQUIPMENTAUXILIARYEQUIPMENTFORMONITORING,MEASURING,MANIPULATION,CONTROLANDPROTECTIONOFPRIMARYEQUIPMENTSUCHASVARIOUSRELAYS,SIGNALDEVICES,MEASURINGINSTRUMENTS,RECORDINGRECORDINGDEVICESANDTELEMETRY,REMOTESIGNALDEVICESANDAVARIETYOFCONTROLCABLES,SMALLBUSES,ETC4,HIGHVOLTAGECIRCUITBREAKERANDHIGHVOLTAGESWITCH,ITCANNOTONLYCUTOFFTHELOADCURRENTANDLOADCURRENTHIGHVOLTAGECIRCUITORCLOSED,ANDWHENAFAULTOCCURS,THEEFFECTOFTHERELAYPROTECTIONDEVICE,CUTOFFTHEOVERLOADCURRENTANDSHORTCIRCUITCURRENTITHASAPERFECTARCEXTINGUISHINGSTRUCTUREANDSUFFICIENTBREAKINGCAPACITY5、LOADSWITCHTHESTRUCTUREOFTHELOADSWITCHISSIMILARTOTHESECRETISOLATINGSWITCH,BUTONLYASIMPLEARCEXTINGUISHINGDEVICEISINSTALLEDITALSOHASANOBVIOUSDISCONNECTIONPOINT,WHICHHASACERTAINBREAKINGCAPACITY,CANOPERATEWITHLOAD,BUTCANNOTDIRECTLYDISCONNECTTHESHORTCIRCUITCURRENT,IFNECESSARY,RELYONTHEHIGHVOLTAGEFUSECONNECTEDWITHITTOACHIEVE6,AIRCIRCUITBREAKERAUTOMATICSWITCHISAMANUALORELECTRICCLOSING,KEEPCLOSINGPOSITIONFORLOCKING,LOWVOLTAGESWITCHTRIPPINGMECHANISMBYACTINGONTHETRIPANDHASANARCEXTINGUISHINGDEVICE,ISWIDELYUSEDINACANDDCDEVICEINTHE500VBELOW,WHENTHECIRCUITOVERLOAD,SHORTCIRCUIT,VOLTAGEDROPORDISAPPEAR,CANAUTOMATICALLYCUTOFFTHECIRCUIT7,CABLETHECOREWIRECONDUCTIVEPART,PLUSINSULATIONLAYERANDPROTECTIVELAYEROFTHREEPARTSOFTHEWIRECALLEDCABLE8,BUSBUSISACOLLECTIONOFEQUIPMENTANDELECTRICALPATHDISTRIBUTIONOFELECTRICENERGY,WHICHDETERMINESTHENUMBEROFEQUIPMENTDISTRIBUTIONDEVICE,ANDSHOWTHATINWHATWAYTOCONNECTTHEGENERATOR,TRANSFORMERANDLINE,ANDHOWCONNECTEDTOTHESYSTEMTOCOMPLETETHETASKOFTRANSMISSIONANDDISTRIBUTION9,CURRENTTRANSFORMERALSOKNOWNASINSTRUMENTCONVERTER,ISALARGECURRENTINTOSMALLCURRENTINSTRUMENT10TRANSFORMERASTATICELECTRICALEQUIPMENT,WHICHISUSEDTOCHANGETHEACVOLTAGEOFACERTAINVALUEINTOANOTHERONEORSEVERALKINDSOFACVOLTAGEWITHDIFFERENTVALUES11,HIGHVOLTAGEELECTROSCOPETOCHECKTHEHIGHPRESSURENETWORKDISTRIBUTIONEQUIPMENT,OVERHEADLINESANDCABLESARECHARGEDTOOLS12,GROUNDWIREINORDERTOPOWEREQUIPMENTANDLINESONTHEACCIDENTVOLTAGEOCCURSUNEXPECTEDLYTOENSURETHATTHEIMPORTANTTOOLFORSTAFFACCORDINGTOTHEMINISTRYREGULATIONS,THEGROUNDINGWIREMUSTBEMADEOFBARECOPPERFLEXIBLEWIREABOVE25MM213,SIGNTOWARNPEOPLENOTTOEQUIPMENTANDCHARGEDPART,INDICATINGFORTHEWORKPLACE,TOREMINDTHESECURITYMEASURES,ANDTHEPROHIBITIONOFCERTAINEQUIPMENTORAMICROPOWERLINECLOSINGNOTICESIGNITCANBEDIVIDEDINTOWARNINGCLASS,PERMITTEDCLASS,PROMPTCLASSANDFORBIDDENCLASS14FENCEINORDERTOPREVENTTHESTAFFHASNOINTENTIONTOTOUCHTHEPARTOFLIVEEQUIPMENTANDINSTALLTHEEQUIPMENTOFSCREENPROTECTION,DIVIDEDTEMPORARYSHELTERANDPERMANENTFENCETWOKINDS15,INSULATIONRODALSOKNOWNASROD,INSULATIONROD,JOYSTICKANDSOONTHEINSULATINGRODISCOMPOSEDOFTHREEPARTSTHEWORKINGHEAD,THEINSULATINGRODANDTHEHANDLEITISUSEDFORCLOSINGOROPENINGHIGHVOLTAGEISOLATINGSWITCH,INSTALLINGANDREMOVINGPORTABLEGROUNDWIRE,ANDFORMEASURINGANDTESTING16,STEPVOLTAGEIFTHEREISAPOTENTIALDIFFERENCEBETWEENTWOPOINTSONTHEGROUNDHORIZONTALDISTANCEOF08M,WHENTHETWOFEETCONTACTTHETWOPOINTS,THEBODYWILLBEARTHEVOLTAGE,THISVOLTAGEISCALLEDSTEPVOLTAGETHEMAXIMUMSTEPVOLTAGEAPPEARSBETWEENTHEGROUNDDISTANCE08MANDTHEGROUNDINGBODYATTHEGROUNDLEVELOFTHEGROUNDINGBODY17,PHASESEQUENCETHATISTHEORDEROFTHEPHASE,THEINSTANTANEOUSVALUEOFALTERNATINGCURRENTFROMNEGATIVETOPOSITIVECHANGETHROUGHTHEZEROORDER18POWERNETWORKSPOWERNETWORKSAREPARTOFTHEPOWERSYSTEM,ITISCOMPOSEDOFVARIOUSTYPESOFSUBSTATIONSTATIONANDVARIOUSVOLTAGELEVELOFTRANSMISSIONANDDISTRIBUTIONLINECONNECTEDCOMPONENTSOFTHEUNIFIEDNETWORK19,ELECTRICPOWERSYSTEMISAPARTOFPOWERSYSTEM,WHICHISCOMPOSEDOFGENERATORANDPOWERDISTRIBUTIONEQUIPMENTINPOWERPLANT,STEPUPANDSTEPDOWNSUBSTATION,POWERTRANSMISSIONANDDISTRIBUTIONLINESANDELECTRICITYTHEEQUIPMENT20,POWERSYSTEMPOWERPLANTS,SUBSTATIONSANDUSERSOFELECTRICITYEQUIPMENT,THEINTERPHASEBETWEENTHEPOWERGRIDANDTHERMALNETWORKORHYDRAULICSYSTEMCONNECTEDTOTHEOVERALLCALLEDPOWERSYSTEMTWO,MULTIPLECHOICEQUESTIONS1,TWORATEDVOLTAGEOFTHESAMERESISTANCE,SERIESCONNECTEDINTHECIRCUIT,THELARGERRESISTANCEAA,CALORIFICVALUEB,CALORIFICVALUEISSMALLC,THEREISNOOBVIOUSDIFFERENCE2THESWITCHOFMULTIMETERISREALIZEDAA,SWITCHOFVARIOUSMEASURINGTYPESANDRANGES,SWITCHCONCURRENTOFMULTIMETER,SWITCHBFORMEASURINGTHEMEASUREDSUBSTANCE3,INSULATIONRODSHOULDBENORMALBA,PLACEDASTABLEB,SOTHATTHEYDONOTCONTACTWITHTHEGROUNDANDTHEWALL,TOPREVENTDAMPDEFORMATIONC,PLACEDINTHECORNER4THETESTCYCLEOFINSULATINGGLOVESISBA,ONCEAYEAR,CONCEAMONTH,SIXMONTHS,ONCEEVERYFIVEMONTHS,B5THETESTPERIODOFINSULATINGBOOTSISBA,ONCEAYEAR,CONCEAMONTH,SIXMONTHS,ONCEEVERYTHREEMONTHS,B6WHENYOUNEEDTOMOVEORCROSSTHEBARRIERDURINGDUTYCA,MUSTHAVELEADERSHIPPRESENCEB,MUSTFIRSTPOWEROUTAGEC,MUSTHAVEAGUARDIANPRESENCE7,DUTYPERSONNELPATROLHIGHVOLTAGEEQUIPMENTAA,THERELAYITSELFDROPSORLIGHTSINDICATEB,SHOULDIMMEDIATELYSWITCHONTHELIGHTANDAUDIOCIRCUITC,SHOULDBEONESIDEITSELFDROPCARD,WHILETHECONTACTCLOSEDTOCONNECTOTHERSIGNALS18WHENTHELINEFAILS,THERELAYPROTECTIONDEVICECANQUICKLYREMOVETHEFAULTPARTANDBA,AUTOMATICRECLOSINGONCEB,SENDSIGNALC,WILLCONTINUETORUNTHEINTACTPART19WHENINSTALLINGEARTHWIRE,ITSHOULDBEBA,INSTALLTHEPHASEB,FIRSTINSTALLTHEGROUNDINGEND,ANDTHENINSTALLTHETWOSIDESOFTHEC,FIRSTINSTALLTHEWIREEND20WHENWEARINGGLOVES,THECOATCUFFSASHOULDBEPUTINTOUSEA,PUTININSULATEDGLOVESB,ROLLUPC,SETOUTSIDETHEGLOVE21,ALINESWITCHPOWEROUTAGEREPAIR,LINESIDEBYPASSOPERATION,ATTHISTIMESHOULDBEONTHESWITCHHANDLEHANGINGCSIGNA,INTHISWORKB,PROHIBITCLOSINGC,PROHIBITCLIMBING,HIGHVOLTAGEDANGERTHREE,FILLINTHEBLANKS,FILLINTHEBLANKS1,SAFETYWORKREGULATIONISSTIPULATEDINTHEFOLLOWINGEQUIPMENTTOEARTHVOLTAGEHIGHERTHAN250VISHIGHVOLTAGEBELOW250VISLOWVOLTAGESAFETYVOLTAGEISBELOW36VSAFETYCURRENTISBELOW10MA2,THEDUTYSTAFFSHOULDREMOVETHEWORKBARRIERFORWORK,THEREQUIREDSAFETYDISTANCEIS07MAT10KV,1MAT35KV,15MAT110KV,3MAT220KV3,THUNDERSTORMSNEEDTOPATROLTHEOUTDOORHIGHVOLTAGEEQUIPMENT,SHOULDWEARINSULATEDBOOTS,ANDMAYNOTBECLOSETOTHELIGHTNINGARRESTER,LIGHTNINGANDGROUNDINGDEVICE4,INCASEOFELECTRICALEQUIPMENTFIRE,SHOULDIMMEDIATELYCUTOFFTHEPOWERSUPPLYOFTHEEQUIPMENT,ANDTHENFIRE5,THEOPERATINGDUTYCOMMONTOOLPLIERS,SCREWDRIVER,ELECTRICKNIFE,SPANNER,PLIERS,ELECTRICIRONANDLOWVOLTAGETESTPENCILETC6INTHEGRAPHICSYMBOLOFTRANSFORMER,YREPRESENTSTHREEPHASECOILSTARCONNECTION7THECONTROLROOMSIGNALINSUBSTATIONISGENERALLYDIVIDEDINTOVOLTAGESIGNAL,CURRENTSIGNAL,RESISTANCESIGNALIN8,PROHIBITEDTHEUSEOFELECTRICEQUIPMENTAROUNDTHETAPE,LINERULER,AMETALRULERANDMEASURINGWORK9,LIVEEQUIPMENTSHOULDUSEDRYPOWDER,1211,CARBONDIOXIDEFIREEXTINGUISHERS,FIREEXTINGUISHERSSHALLNOTUSEFOAMEXTINGUISHER10THECOMMONDCPOWERSUPPLYINSUBSTATIONISBATTERY,SILICONRECTIFIERANDCAPACITORENERGYSTORAGE11,THESUBSTATIONLIGHTINGACCIDENTMUSTBEINDEPENDENTPOWERSUPPLY,ANDTHECOMMONLIGHTINGCIRCUITCANNOTBEMIXED12,THEHIGHVOLTAGECIRCUITBREAKERORDISCONNECTINGSWITCHSHOULDBEOPENEDANDCLOSED13,THERELAYPROTECTIONDEVICEANDAUTOMATICDEVICESWITCHINGOPERATIONTERMSSHOULDBEINPUTANDRELEASE14THEOPERATIONTERMSOFCHECKINGANDINSTALLINGGROUNDINGWIRESAREINSTALLATIONANDDISMANTLING15,EACHOPERATIONTICKETCANONLYFILLATASK,EACHOPERATIONOFA,A“TICKMARK“16THEEXECUTEDOPERATINGNOTESINDICATE“EXECUTED“INVALIDOPERATIONSHOULDBEMARKED“INVALID“WORDTHETWOOPERATIONTICKETSSHOULDBEKEPTFORATLEASTTHREEMONTHS17,INTHEOUTPUTCHARACTERISTICSOFTHETRANSISTOR,THEREARETHREEREGIONSAREINTERCEPT,AMPLIFICATIONREGIONANDSATURATIONREGION18、INTHESERIESCIRCUITOFRESISTANCE,CAPACITANCEANDSENSE,ONLYRESISTORSCONSUMEELECTRICALENERGY,ANDINDUCTANCEANDCAPACITANCEAREJUSTENERGYTRANSFORMATIONS19,THESUBSTATIONSTATIONSWITCHINGOPERATIONMUSTBEIMPLEMENTEDBYTWOPEOPLE,WHICHISFAMILIARWITHTHEEQUIPMENTGUARDIAN20,INTHEOPERATIONOFTHESWITCH,IFTHEREISDOUBT,NOTALLOWEDTOCHANGETHEOPERATIONTICKET,TOBEONDUTYDISPATCHERORHEADOFDUTYREPORT,CLEARAFTEROPERATION21,INTHESUBSTATIONTHEOPERATION,DONOTFILLINTHEOPERATIONTICKETWORKACCIDENTHANDLING,PULLSWITCH,SINGLEOPERATION,OPENTHEGROUNDINGSWITCHORREMOVEDONLYAGROUPOFEARTHWIREFACTORY22,FILLINTHEOPERATIONORDER,INCLUDINGTHEOPERATIONSEQUENCE,OPERATION,OPERATOR,GUARDIANANDOPERATIONTIME,ETC23,HIGHVOLTAGEEQUIPMENTGROUNDINGFAULTOCCURS,THESAFETYDISTANCEOFTHEBODYGROUNDINGINDOORSHOULDBEGREATERTHAN4M,OUTDOORSHOULDBEGREATERTHAN8M24THEPRIMARYCURRENTOFTHECURRENTTRANSFORMERISDETERMINEDBYTHELOADCURRENTOFTHEPRIMARYCIRCUIT,ANDITDOESNOTCHANGEWITHTHEIMPEDANCEOFTHETWOCIRCUIT,WHICHISTHEMAINDIFFERENCEFROMTHEWORKINGPRINCIPLEOFTHETRANSFORMER25,THEROLEOFTRANSFORMEROILPILLOWISTOADJUSTTHEAMOUNTOFOIL,EXTENDTHESERVICELIFEOFTHEOILTHEVOLUMEOFTHEOILPILLOWISGENERALLY1/10OFTHETOTALTRANSFORMER26,WHENTHETRANSFORMERINTERNALFAULT,THEGASRELAYONTHECONTACTSIGNALCIRCUIT,THEGROUNDCONNECTIONSWITCHTRIPPINGCIRCUIT27,THECOOLINGMETHODOFTRANSFORMEROILIMMERSEDNATURALCOOLING,OILCOOLING,COOLINGANDFORCEDOILCOOLINGOILSTRONG28THERATEDCURRENTOFTHEMAINEQUIPMENTINOURFACTORY,1000KVATRANSFORMER577,J752A5251J201166AIPLANT,THREEYEARS,ANDRODENTACCIDENTSMAINLYDAMAGEDEQUIPMENT,AND29QUESTIONSANDANSWERSOFFOURQUESTIONSANDANSWERSWHATISTHEUSEOFRELAYPROTECTION,1ANSWER1,WHENTHEGRIDISENOUGHTODAMAGETHEEQUIPMENTFAILUREORENDANGERTHESAFEOPERATIONOFPOWERGRID,THEEQUIPMENTTOBEPROTECTEDFROMPOWERGRIDTHENONNORMALSTATE,THENONNORMALOPERATIONOFPOWERGRIDANDSOMEDEVICESCANPROMPTLYISSUEDAWARNINGSIGNAL,SOASTOMAKERAPIDPROCESSING,THERETURNTONORMALANDREALIZETHEAUTOMATIONOFELECTRICPOWERSYSTEMSANDREMOTECONTROL,ANDAUTOMATICCONTROLOFINDUSTRIALPRODUCTION2,THEBASICPRINCIPLEOFRELAYPROTECTIONDEVICEISWHATAFAULTOCCURSINPOWERSYSTEM,THEBASICCHARACTERISTICSOFTHECURRENTSURGEVOLTAGE,ANDTHEPHASEANGLEBETWEENCURRENTANDVOLTAGECHANGES,VARIOUSRELAYPROTECTIONDEVICEISTOSEIZETHESECHARACTERISTICS,BASICPHYSICALQUANTITYCHANGESINRESPONSETOTHESETHINGS,THEUSEOFNORMALWITHTHEFAULT,THESCOPEOFPROTECTIONOFINTERNALANDEXTERNALFAULTSANDVARIOUSPHYSICALDIFFERENCESINTHEAMOUNTOFPROTECTIONREALIZATION,THEREISINCREASINGREACTIONCURRENTOVERCURRENTPROTECTION,LOWVOLTAGEPROTECTIONREACTIONREDUCEDVOLTAGE,THEREISCURRENTANDREACTIONREACTIONPHASEANGLECHANGETHEDIRECTIONOFTHECURRENTPROTECTIONANDDISTANCEPROTECTIONREACTIONVOLTAGEANDCURRENTRATIOETC3,WHATARETHEREQUIREMENTSOFTHERELAYANSWER1THEERROROFTHEACTIONVALUEISSMALL,THECONTACTPOINTISRELIABLE,THERETURNTIMEISSHORT,ANDTHEPOWERCONSUMPTIONISSMALLANSWERACCORDINGTOTHEPHYSICALQUANTITYOFSENSINGELEMENTRESPONSE,4,WHICHTYPESOFRELAYSARECOMMONLYUSEDRELAYCANBEDIVIDEDINTOTWOKINDSOFELECTRICITYANDNONELECTRICITY,BELONGINGTONONELECTRICGASRELAY,SPEEDRELAY,TEMPERATURERELAY,ETCTHEREAREMANYKINDSOFREACTIONPOWERISGENERALLYDIVIDEDINTO1,ACCORDINGTOTHEPRINCIPLEOFACTIONISDIVIDEDINTOELECTROMAGNETICINDUCTIONTYPE,TYPE,TYPE,TYPEOFTRANSISTORRECTIFIER2,ACCORDINGTOTHENATUREOFREACTIONPOWERACURRENTRELAYANDAVOLTAGERELAYTHIRDLY,ACCORDINGTOTHEFUNCTIONCANBEDIVIDEDINTOELECTRICRELAY,TIMERELAYANDSIGNALRELAY5WHATARETHEINSPECTIONITEMSOFINDUCTIONTYPECURRENTRELAYANSWERINDUCTIONTYPECURRENTRELAYOVERCURRENTRELAY,WHICHINCLUDESFAULTELEMENTSENSINGELEMENTANDSPEED,THECOMMONLYUSEDMODELSFORGL10ANDGL20TWOSERIES,INTHEINSPECTIONANDREGULARINSPECTION,THEINSPECTIONITEMSAREASFOLLOWSFIRST,THEINTERNALANDEXTERNALINSPECTIONMECHANICALPARTSINSPECTIONTHIRD,THEINSULATIONTESTCURRENT,INITIALINSPECTION5,ACTIONANDTHERETURNVALUE,THESPEEDOFPNEUMATICCOMPONENTSINSPECTIONINSPECTIONINSPECTION,THEACTIONTIMECHARACTERISTICTHECONTACTRELIABILITYTEST6HOWTOCORRECTLYUSEGROUNDSHAKINGMETERANSWERBEFOREMEASURING,THEFIRSTTWOPROBEWEREINSERTEDINTOTHEEELECTRODEINTHEPOTENTIALANDCURRENTPROBEPPROBECINASTRAIGHTLINEAND20METERSAPART,PEANDINSERTEDINTOC,THENUSESPECIALWIRERESPECTIVELYCORRESPONDINGTOTERMINALE,P,CONTHERECEIVINGINSTRUMENTWHENMEASURINGTHEFIRSTPOINTERINSTRUMENTONAHORIZONTALPOSITIONTOCHECKWHETHERTHEGALVANOMETERREFERSTOTHECENTERLINE,ORBYZEROADJUSTER,THEPOINTERADJUSTMENTTOTHECENTERLINE,THENTHEINSTRUMENT“RATESCALE“ATTHEMAXIMUMMULTIPLESLOWLYROTATINGCRANKGENERATOR,ATTHESAMETIME,THE“MEASUREMENTSCALE“MAKEGALVANOMETERPOINTERBALANCE,WHENTHEPOINTERNEARTHECENTERLINE,SPEEDUPTHEGENERATORCRANKSPEEDUPTO120RPM,ANDTHENADJUSTTHE“MEASUREMENTSCALE“INTHECENTEROFTHEPOINTERLINE,“MEASURINGDIALREADINGS“MULTIPLIEDBY“TIMESRATESCALING“MULTIPLEISTHEMEASUREDRESISTANCEVALUE7WHATEXTERNALINSPECTIONSSHOULDRELAYSBECARRIEDOUTANSWERTHERELAYSHOULDDOTHEFOLLOWINGEXTERNALINSPECTIONINTHEREGULARINSPECTIONORAPPROVAL1,THERELAYSHELLSHOULDBEINTACT,ANDTHEBASEOFTHECOVERTHECOMPONENTSSHOULDNOTHAVETRAUMAANDDAMAGE,ANDINSTALLEDBYTHEFIRMANDNEATTHESCREW,TERMINALANDTHECONDUCTIVEPARTCONNECTINGWIREPARTSSHOULDNOTOPENWELDINGANDOXIDATIONBADCONTACTPHENOMENON,THESCREWANDTHETERMINALSHOULDHAVEWASHERSANDSPRINGPADTHENONCONDUCTIVEPART,SUCHASASPRING,ALIMITROD,MUSTBEFIXEDWITHSCREWSANDDURABLEPAINTANDSEAL8WHATISTHETRANSFORMERINSULATIONABSORPTIONRATIOANSWERINTHEREPAIRANDMAINTENANCEOFTRANSFORMER,NEEDINSULATIONABSORPTANCEMEASUREMENTOFTRANSFORMER,ITISEQUALTO60SECONDSOFTHEMEASUREDVALUEOFINSULATIONRESISTANCERATIOOFR60/B15ABSORPTIONRATIOCANBEASTEPTOJUDGEWHETHERTHEHUMIDINSULATIONANDINSULATIONRESISTANCEIN15SECONDSOFTHEMEASUREDVALUE,DIRTYORDEFECTIVE,THERULESIN1030C,3560KVWINDINGISNOTLESSTHAN12110330KVWINDINGISNOTLESSTHAN139WHATARETHEINSPECTIONITEMSOFDX11TYPESIGNALRELAYANSWER1EXTERNALINSPECTION2INTERNALANDMECHANICALPARTINSPECTION3INSULATIONTEST4DCRESISTANCEMEASUREMENT5TESTOFACTIONVALUETHECONTACTRELIABILITYTEST10HOWTOCHECKTHERETURNVALUEOFTHEACTIONVALUEOFDX11SIGNALRELAYATHETESTWIRINGISTHESAMEASTHATOFTHEINTERMEDIATERELAYFORTHECURRENTTYPERELAY,ITSOPERATIONVALUESHOULDBE7090OFTHERATEDVALUEFORTHEVOLTAGETYPESIGNALRELAY,ITSOPERATIONVALUESHOULDBE5070OFTHERATEDVALUETHERETURNVALUESHALLNOTBELESSTHAN5OFTHERATEDVALUEIFTHEOPERATIONVALUEANDTHERETURNVALUEDONOTMEETTHEREQUIREMENTS,THESPRINGTENSIONORTHEDISTANCEBETWEENTHEARMATUREANDTHEIRONCORECANBEADJUSTED11WHATISTHESELECTIVITYOFRELAYPROTECTIONDEVICESANSWERPROTECTIONBYSELECTIVEPROTECTIONSCHEMEANDSETTINGCALCULATIONOFTHEDECISION,WHENAFAULTOCCURS,THERELAYPROTECTIONDEVICECANRAPIDLYANDACCURATELYFAULTEQUIPMENTREMOVED,THEHARMCAUSEDBYTHEFAULTANDTHEPOWERRANGEISREDUCEDASFARASPOSSIBLE,SOASTOENSURETHENORMALOPERATIONOFEQUIPMENTTONONFAULTPROTECTIONDEVICE,CANMEETTHEABOVEREQUIREMENTS,ARECALLEDSELECTIVE12WHATARETHEADVANTAGESOFTHEQUICKACTIONOFTHERELAYPROTECTIONDEVICEANSWER1,QUICKACTION,QUICKLYREMOVETHEFAULT,CANREDUCETHEUSERINREDUCINGVOLTAGEWORKINGTIME,ACCELERATETHEPROCESSOFNORMALOPERATION,RAPIDRECOVERYTHEREMOVALOFFAULTS,THEEXTENTOFTHEDAMAGECANREDUCETHEELECTRICALEQUIPMENTFAILUREAFFECTEDTHERAPIDREMOVALOFFAULT,FAULT,CANPREVENTTHEEXPANSION13WHATARETHECHARACTERISTICSOFCURRENTFASTBREAKINGPROTECTIONANSWERNOTIMECURRENTFASTBREAKCANNOTPROTECTTHEFULLLENGTHOFTHELINE,ITCANONLYPROTECTPARTOFTHELINE,THESYSTEMOPERATIONMODECHANGES,WILLAFFECTTHECURRENTFASTBREAKPROTECTIONRANGE,INORDERTOENSURETHESELECTIVITYOFACTION,SECOND,NOTONLYCANMANUALREMOTECONTROLSHOULDALSOBEABLETOCARRYOUTTHEAUTOMATICTRIPPINGANDCLOSINGINPROTECTIONORAUTOMATICDEVICE3,TOREFLECTTHEPOSITIONSIGNALOFTHECIRCUITBREAKERCLOSINGORTRIPPINGSIGNAL,TOHAVETHEOBVIOUSDIFFERENCEBETWEENMANUALANDAUTOMATICJUMPCLOSING5,TOPREVENTTHECIRCUITBREAKERCLOSINGTIMESTHE“JUMP“LOCKINGDEVICETHEINTEGRITY,CANMONITORTHEPOWERSUPPLYANDTHENEXTOPERATIONLOOP16WHATISTHE“GROUND“ONTHEELECTRICALANSWERELECTRICALEQUIPMENTINOPERATION,IFTHEGROUNDFAULTOCCURS,THENTHESHORTCIRCUITCURRENTTHROUGHTHEGROUNDINGBODY,ANDTHEHEMISPHERICALSURFACEFORMEDINTHEDIASPORA,ASSHOWNINTHEFIGURE,THEHEMISPHERICALSURFACEISSMALLANDTHEFLOWRESISTANCEINCREASES,THESHORTCIRCUITCURRENTBYTHEVOLTAGEDROPISBIGGERHERETHEREFORE,NEARTHEGROUNDINGBODY,THEHEMISPHEREISSMALL,THERESISTANCEISLARGE,THECURRENTHEREISHIGH,ANDCONVERSELY,INTHEFARDISTANCEGROUNDINGBODY,BECAUSETHEHEMISPHEREISLARGE,THERESISTANCEISSMALL,THEPOTENTIALISLOWEXPERIMENTSHAVESHOWNTHAT,INTHEABSENCEOFASINGLEGROUNDINGORGROUNDINGELECTRODE20M,THESPHEREISALREADYVERYLARGE,ITSRESISTANCEISZERO,WHEREWECALLTHEPOTENTIALEQUALTOZERO,CALLEDELECTRICALANDGROUND“17WHATISTHESHORTCIRCUITVOLTAGEOFTHETRANSFORMERANSWERSHORTCIRCUITVOLTAGEISONEOFTHEMAINPARAMETERSOFTHETRANSFORMER,ITISTHROUGHTHESHORTCIRCUITTESTMEASURED,THEMEASUREMENTMETHODISTHESECONDARYSIDEOFTHETRANSFORMERSHORTCIRCUITCURRENT,PRIMARYSIDEPRESSURETOREACHTHERATEDVALUE,THEVOLTAGEOFVDPRIMARYSIDEANDCALLEDSHORTCIRCUITVOLTAGE,SHORTCIRCUITVOLTAGEISGENERALLYUSEDPERCENTILESAID,INGENERAL,THESHORTCIRCUITVOLTAGEINDICATEDBYTHENAMEPLATEOFTRANSFORMERISEXPRESSEDASTHEPERCENTAGEOFTHESHORTCIRCUITVOLTAGEVDANDTHERATEDVOLTAGEVEOFTHEWINDINGWHICHISPRESSEDUNDERTEST,THATIS,VDVDE/VE10018WHATMATTERSSHOULDBEPAIDATTENTIONTOWHENMEASURINGTHECAPACITORANSWER1WHENMEASURINGWITHMULTIMETER,THEAPPROPRIATEGEARSHOULDBESELECTEDACCORDINGTOTHECAPACITORANDRATEDVOLTAGEFOREXAMPLECAPACITORUSEDINELECTRICPOWEREQUIPMENT,GENERALLYATALOWVOLTAGEOFONLYAFEWVOLTSTOTHOUSANDSOFVOLTS,IFUSINGAMULTIMETERR1CKGEARMEASUREMENT,BECAUSETHEVOLTAGEINTHETABLEIS15225VOLTBATTERY,ISLIKELYTOMAKETHECAPACITORBREAKDOWN,ITSHOULDUSER1KFILE,FORTHEMEASUREMENTCAPACITORJUSTREMOVEDFROMTHELINE,MUSTDISCHARGETHECAPACITORBEFORETHEMEASUREMENT,INORDERTOPREVENTTHEREMNANTSOFTHECHAIRINTHECAPACITORTODISCHARGETHEINSTRUMENT,THEINSTRUMENT,THEDAMAGEFORHIGHEROPERATINGVOLTAGE,LARGECAPACITYCAPACITOR,ENOUGHTODISCHARGETHECAPACITOR,THEOPERATORSSHOULDBEPROTECTIVEMEASURESTOPREVENTTHEDISCHARGEELECTRICSHOCKACCIDENT19WHATISSINEALTERNATINGCURRENTWHYSINEWAVECURRENTISWIDELYUSEDNOWADAYSANSWERSINUSOIDALALTERNATINGCURRENTREFERSTOTHESIZEA