1、ModernfrequencychangertechnicalanalysisChengXi(Heilongjianglongmaymininggroupco//ltd/)Thegeneralfrequencychangerbyitsmeritsandsoonintellectualization/digitization/networkreceivespeoplesfavormoreandmore/butalongwiththegeneralfrequencychangerapplicationscopesexpansion/exposessomequestions/Inviewofthes
2、equestions/thisarticlecarriedonhasanalyzedandproposedthecountermeasure/First/overtonequestionandcountermeasure/Thegeneralfrequencychangersmaincircuitformgenerallybytherectificationpart/thecontravariantpartandthefilterpartiscomposed/Therectificationpartforthethree-phasebridge-typeuncontrolledrectifie
3、r/theinvertorspartistheIGBTthree-phasebridge-typeinvertors/andtheoutputisthePWMprofile/Becausethegeneralfrequencychangersrectificationpartusesthediodeuncontrolledbridge-typelevelingcircuit/themiddlefilterpartusesthebigelectriccapacitytotakethefilter/thereforerectifiersinputcurrentinfactiscapacitorsc
4、hargingcurrent/assumesahighermoreandprecipitouspulsewave/itsharmoniccomponentisbig/Fortheharmoniccancellation/mayuse/1/Increasesthefrequencychangerelectricpowersupplyinternalresistance/Usuallyinthesituation/powerequipmentsinternalresistancemayplaythecushionfrequencychangerconcurrentfilterelectriccap
5、acitysreactivepowerrole/Thiskindofinternalresistanceistransformersshort-circuitimpedance/Whenpowersourcecapacityrelativefrequencychangercapacityhour/thentheinternalresistancevaluerelativelyisbigger/theharmoniccontentissmaller；Whenthepowersourcecapacityrelativefrequencychangercapacityisbigger/thenthe
6、internalresistancevaluerelativelyisbigger/theharmoniccontentisbigger/Thereforebestchoiceshort-circuitimpedancebigtransformer/2/Installsthereactor/Installsthereactorisactuallyincreasesthefrequencychangerelectricpowersupplysinternalresistancefromexterior/Installsthedirect-currentreactorinfrequencychan
7、gersexchangesideinstallmentexchangereactororinfrequencychangersdirect-currentside/alsoorinstalls/suppressestheharmoniccurrent/3/Transformerheterogeneitymovement/Thegeneralfrequencychangersrectificationpartissixpulsewaverectifiers/thereforeproducestheovertoneisbig/Ifusingtransformersheterogeneitymove
8、ment/causesphaseanglemutualdeviation30likeY-/-thecombinationtwotransformerconstitutiontobeequalto12pulsewaveeffects/thenmayreducetheloworderharmoniccurrent28%/playstheharmonicsuppressionrole/4/Adjustsfrequencychangerscarrierratio/Solongascarriercomparedtoenoughbig/isinferiortheovertonetobepossibleto
9、suppresseffectively/speciallythereferencewavepeak-to-peakvalueandthecarrierpeak-to-peakvaluearesmallerthan1/00/13followingoddnumberovertonesnolongerappear/5/Special-purposefilter/Thespecial-purposefilteruseinexaminingthefrequencychangerharmoniccurrentthepeak-to-peakvalueandthephase/andproducesonewit
10、htheharmoniccurrentpeak-to-peakvaluetobethesame/butthephasejustrightoppositeelectriccurrent/passesthroughinthefrequencychanger/absorptionharmoniccurrent/Second/matchingofloadquestionandcountermeasure/Producesmachinerystorquecharacteristicstodivideintothreetypesroughly/Permanenttorqueloading/airblowe
11、rpumpclassloadandpermanentpowertermination/Inviewofthedifferentloadtype/shouldchoosethedifferenttypethefrequencychanger/1/Permanenttorqueloading/Thepermanenttorqueloadingisreferstotheloadmomenttohavenothingtodowiththerotationalspeed/underanyrotationalspeed/thetorquemaintainsconstant/Butthepermanentt
12、orqueloadingdividesintothefrictionclassloadandthepotentialenergytypecapacitytwokinds/2/Airblowerpumpclassload/Theairblowerpumpclassloadispresentindustryfieldapplicationmostequipment/althoughthepumpandairblowerscharacteristicaremanyandvaried/butmainlybythecentrifugalpumpandthecentrifugalfanapplicatio
13、n/thegeneralfrequencychangersareprimarilymostinthiskindofloadapplication/Thiskindofloadisnothightofrequencychangersperformancerequirement/onlyrequeststheefficiencyandthereliability/thereforethechoicehastheU/f=constcontrolmodelfrequencychangerthen/likeMitsubishifrequencychangerFR-F540(L)series/Airblo
14、werloadinactualmovementprocess/becausetherotorinertiaisquitebig/thereforefrequencychangersrisetimeandthedecelerationtimeareaveryimportantquestion/Theairblowerloadssystemrotorinertiacomputationisveryimportant/Whenfrequencychangerconcretedesign/accordingtothecomputedresult/carriesonthesuitablerevision
15、/whenthefrequencychangerstartsdoesnotoccurtheoverflowtripandthefrequencychangerdeceleratewhendoesnothaveintheovervoltagetripsituation/choiceshortesttime/Butthepumpclassloadintheactualmovementprocess/easytohavethebuzz/thebuildthepressureandthewaterhangstheeffect/thereforetimefrequencychangershaping/m
16、ustchooseissuitableforthepumpclassloadthefrequencychanger/andfrequencychangerinfunctionhypothesistimemustaimattheabovequestiontocarryonestablishesalone/3/Permanentpowertermination/Thepermanentpowerterminationreferstotheloadwhichthetorqueroughlyandtherotationalspeedisinreverseproportion/likecoiler/un
17、windingcoilerandsoon/Speakingofcertainspeedchangescope/whenactuatesthepermanentpowerterminationusingthefrequencychanger/usuallytheconsiderationselectsthepermanenttorquevelocitymodulationmethodbelowsomerotationalspeed/whenishigherthanthisrotationalspeedonlythenselectsthepermanentpowervelocitymodulati
18、onmethod/Usuallyiscalledthisrotationalspeedspotsthebasefrequency/butthispointcorrespondencesvoltageoutputstheratedvoltageforthefrequencychanger/Third/givesoffheatthequestionandthecountermeasure/Frequencychangersgivingoffheatisproducesbytheinternalloss/Carriesontheradiationtothefrequencychanger/usual
19、lyuse/1/Usestheventilatorradiation/Frequencychangersinternalinstallationventilatormaycarryofffrequencychangersboxbodyinteriorradiation/iftheventilatorcannotthenormalwork/immediatelystopthefrequencychangermovement/2/Reducesinstallstheambienttemperature/Generalfrequencychangersenvironmentoperatingtemp
20、eraturegeneralrequestin-10to-50/ifcantakethemeasuretoreducethefrequencychangeroperatingtemperatureasfaraspossible/thenfrequencychangersservicelifelengthens/theperformanceisalsoquitestable/Mayadopttwomethodsregardingthisquestion/First/constructstheindependentfrequencychangerlowpressure/theinteriorins
21、tallstheairconditioning/maintainsthelowpressurethetemperaturein+15to+20between；Second/frequencychangersinstallmentspaceneedstosatisfythefrequencychangerinstructionforusetherequest/Theabovetalksaboutthefrequencychangergivesoffheatisreferstothefrequencychangerintheratedrangethenormaloperationloss/When
22、thefrequencychangerhastheunusualmovement(forexampleoverflow/whencrossespressure/thelosswhichoverloadandsoon)produces/mustavoidthiskindofphenomenonthroughthenormalshapingtheoccurrence/Regardingtheairblowerpumpclassload/takeMitsubishifrequencychangerFR-F540astheexample/whenthefrequencychangerisopposit
23、einitsratedload120%overloads/itsdurationis60seconds/anddoesnotallowwithin300secondstopresentthesecondoverload/Whenthefrequencychangerpresentstheoverload/becausethepowerunititwindsthroughtheexcesscurrentelevatestemperature/causesthefrequencychangeroverheated/bymustcauseitstemperaturedecreasetocausefr
24、equencychangersoverheatedprotectionmovementassoonaspossibletoeliminate/thisundercookingisfrequencychangersoverloadcycle/Thedifferentfrequencychanger/itsoverloadmultiple/theoverloadtimeandtheoverloadcyclearenotsame/anditsoverloadmultipleisbigger/theoverloadtimeisshorter/Electricalmachinerywhichactuat
25、esregardingthefrequencychanger/maydivideintotwokindsaccordingtoitsworkingcondition/Long-termworkingsystemandredundantshort-timeworkingsystem/Thelong-termworkingsystemselectricalmachinerymayaccorditsnamebrandstipulationdatalong-termmovement/Inviewofthiskindofload/thefrequencychangermaycarryontheshapi
26、ngaccordingtotheelectricalmachinerydataplatedata/likecontinuousrunningoilpump/ifitselectricalmachinerypoweristime22kW/maychoosetheFR-F540-22kfrequencychangerthen/Theredundantshort-timeworkingsystemelectricalmachinery/itscharacteristicistheduplicationandshort-time/namelyelectricalmachinerysoperatingt
27、imeandtheidletimecarriesonalternately/moreoverisquiteshort/thetwosum/accordingtothecountrystipulatedthatdonotsurpassfor60seconds/Theredundantshort-timeworkingsystemelectricalmachinerypermitsitsoverload/andhascertainelevationoftemperature/Thistime/ifchoosesthefrequencychangeraccordingtotheelectricalm
28、achinerydataplatedata/willcreatefrequencychangersdamageinevitably/Inviewofthiskindofload/thefrequencychangerinthereferenceelectricalmachinerydataplatedatassituationmustaccordingtotheelectricalmachineryloaddiagramandfrequencychangersoverloadmultiple/theoverloadtime/andtheoverloadcyclecomestheshaping/Ifisredundanttheshort-timemovementtheelevator/itselectricalmachinerypoweris18/5kW/maychoosetheFR-A540-22Kfrequencychanger/Throughhastheproblemtothegeneralfrequencychangermovementprocessintheanalysis/proposedsolvesthesequestionactualcountermeasure/alongwiththe
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