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简介:Thispaperproposesahybriddecoupledpowerflowmethodforbalancedpowerdistributionsystemswithdistributedgenerationsources.Themethodformulatesthepowerflowequationsinactivepowerandreactivepowerdecoupledformwithpolarcoordinates.Second-ordertermsareincludedintheactivepowermismatchiteration,andconstantJacobianandHessianmatricesareused.Ahybriddirectandindirectsolutiontechniqueisusedtoachieveefficiencyandrobustnessofthealgorithm.Activepowercorrectionissolvedbymeansofasparselowertriangularanduppertriangular(LU)decompositionalgorithmwithpartialpivoting,andthereactivepowercorrectionissolvedbymeansofrestartedgeneralizedminimalresidualalgorithmwithanincompleteLUpre-conditioner.Typicaldistributiongenerationmodelsanddistributionloadmodelsareincluded.Theimpactofzero-impedancebranchesisexplicitlymodeledthroughreconfiguringoftheadjacentbrancheswithimpedances.Numericalexamplesonasampledistributionsystemwithwidespreadphotovoltaicinstallationsaregiventodemonstratetheeffectivenessoftheproposedmethod.
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简介:CentralBusinessDistrict(CBD),aconceptthatwasfirstproposedbyU.S.scholarsinthe1920s,referstoabusinesscenterthatfunctionsasacommercialtrading,finan-cialinformation,culturalcenter,exhibitionandofficeareaallrolledintoone:aplacethatisthecenterofbusiness,thedrivingpowerofurbaneconomicdevelopmentandthesoulofacity.
简介:Intenseclashesofinterestsandcollusionofideassprangupincessantlyamongnationsoverupwardsovereigntytransfer,interestsdistributionandmaintenanceofparityamongpartnersinthecourseofeconomicintegration.Disparitiesinsize,territory,nationalstrengthanddevelopmentlevelconceivablyoftenledtotensionsandevencrisesoverpowerdistribution.SoEUhistorycanbedescribedasoneofcrisesorcrisissettlementthroughreachinganewequilibrium,asignificantprocessforsustainedEUstability.
简介:1.AllpowersupplyunitsundertheStatePowerCorporationshallpublicizepowertariffstandardsandserviceprocedures.2.AllpowersupplyunitsoncountyorhigherlevelundertheStatePowerCorporationshallopentoservice7daysaweek.3.Powersupplysecurity,reliabilityandservicequality
简介:One-dimensionalringpowersystemisdiscreditedtoanumberofnodeseachcontainingageneratorwithinternalreactanceandloadbranchofresistanceandreactancewithacertainpowerfactor.Whenadisturbanceoccursatanymachineinthepowersystem,simulativeanalysisisperformedtoverifyhowthevariationofloadpowerfactoraffectingthebehaviorofelectromechanicalwavepropagationbyusingtheMATLABpackage,fromwhichdifferentsituationsarepresentedanddiscussed.Theseresultsshowthetypeofloadhasnoeffectonthebehaviorofelectromechanicalwavepropagation.
简介:Heathandlinghasbeenasignificantproblemofthehighpowerfiberlasersystemsastheoutputpowerincreasesrapidly.Claddingpowerstripper(CPS)whichisusedtodealwiththeunwantedopticalpowerandlightisrequiredforhighercoolingability.Sothemethodsofstrippingtheunwantedlightattractedmuchattentionrecently,andthethermaleffectisgiven.However,fewinvestigationsfocusonthedissipationoftheheatconvertedfromtheunwantedlight.Inthispaper,anapproachofactivecoolingforCPSisdemonstrated.ThisisachievedbyusingmicrochannelcoolingtechnologyinheatsinkinginCPStoimprovetheefficiencyofheatexchange.InordertoexplainthemechanismofCPSthefunctionofitandconsistenceofcategoriesoftheunwantedlightaredetailedfirstly.Thenmicrochannelheatsinkingisproposedandverifiedbytheheatexchangetheory.Atlast,thedesignoftheCPSwithmicrochannelheatsinkingisshownandfollowingexperimentisconducted.Thefinaltemperatureofthedevicewith1000WcladdingpowerwasdemonstratedatlasttoverifytheabilityofheatdistributionoftheCPScomponent.ThissuggeststhattheseCPSscanbeusedtostripeathousandofwattsoflightinhighpowerdoublecladdingfiberlasers.
简介:<正>London24November2004MotheristhemostbeautifulwordintheEnglishlanguage,accordingtoasurveyofover40,000overseasvotersandlearnersofEnglishatBritishCouncilteachingcentres.ThesurveywasconductedbytheBritishCounciltocoincidewithits70thanniversarycelebrations.TheBritishCouncilaskedover7,000learnersin46countrieswhattheyconsideredtobethemost
简介:Speakervariabilityisanimportantsourceofspeechvariationswhichmakescontinuousspeechrecognitionadifficulttask.Adaptingautomaticspeechrecognition(ASR)modelstothespeakervariationsisawell-knownstrategytocopewiththechallenge.AlmostallsuchtechniquesfocusondevelopingadaptationsolutionswithintheacousticmodelsoftheASRsystems.Althoughvariationsoftheacousticfeaturesconstituteanimportantportionoftheinter-speakervariations,theydonotcovervariationsatthephoneticlevel.Phoneticvariationsareknowntoformanimportantpartofvariationswhichareinfluencedbybothmicro-segmentalandsuprasegmentalfactors.Inter-speakerphoneticvariationsareinfluencedbythestructureandanatomyofaspeaker'sarticulatorysystemandalsohis/herspeakingstylewhichisdrivenbymanyspeakerbackgroundcharacteristicssuchasaccent,gender,age,socioeconomicandeducationalclass.Theeffectofinter-speakervariationsinthefeaturespacemaycauseexplicitphonerecognitionerrors.Theseerrorscanbecompensatedlaterbyhavingappropriatepronunciationvariantsforthelexiconentrieswhichconsiderlikelyphonemisclassificationsbesidespronunciation.Inthispaper,weintroducespeakeradaptivedynamicpronunciationmodels,whichgeneratedifferentlexiconsforvariousspeakerclustersanddifferentrangesofspeechrate.Themodelsarehybridsofspeakeradaptedcontextualrulesanddynamicgeneralizeddecisiontrees,whichtakeintoaccountwordphonologicalstructures,rateofspeech,unigramprobabilitiesandstresstogeneratepronunciationvariantsofwords.EmployingthesetofspeakeradapteddynamiclexiconsinaFarsi(Persian)continuousspeechrecognitiontaskresultsinworderrorratereductionsofasmuchas10.1%inaspeaker-dependentscenarioand7.4%inaspeaker-independentscenario.
简介:Anintelligentcoordinatedcontrolstrategyhasbeenproposedandsuccessfullyappliedtoa300MWboiler-tur-bineuniti.e.Unit1ofYuanbaoshanpowerplantinChina.Loadfollowingoperationofcoal-firedboiler-turbineunitinthepowerplantleadstochangesinoperatingpointswhichresultinnonlinearvariationsoftheplantvariablesandparameters.Forthevariationofoperatingconditionandslowlyvaryingdynamics,anintelligentcontrolschemehasbeendevelopedbycombiningfuzzyself-tuningwithadaptivecontrolandauto-tuningtechniques.Asthereexiststrongcouplingsbetweencontrolloopsofmainsteampressureandpoweroutputintheunit,anewdesignforstaticdecoupleraimedatdecouplingforsetpointsandunmeasuredpulverizedcoaldisturbanceofthesystematthesametimeispresented.Satisfactoryindustrialapplicationresultsshowthatsuchacontrolsystemhasenhancedadaptabilityandrobustnesstothecomplexprocess,andbettercontrolperformanceandhigheconomicbenefithavebeenobtained.
简介:Twomethodsforimprovingtheequidrivingpower-frequencycharacteristicsofbroad-bandhighpowerklystronsarepresented.Oneisthatacomb-linebandpassfilterwithsomeattenuationpropertiesisinsertedbetweentheTWTdriverandtheklystronforcompensatingthegain-frequencycharacteristicsoftheklystrontogettherequiredequidrivingpower-frequencycharacteristics.Theotheristhatareactiveelementisconnectedwiththeinputcavitytochangeitsresonancefrequenciesf0andQL,andthustoimprovethepower-frequencycharacteristicsoftheklystron.