Sensitivity of Personal Computers to Voltage Sags and Short

——均是精品资料,值得下载!下的越多,我越开心了。哈哈

IEEETRANSACTIONSONPOWERDELIVERY,VOL.20,NO.1,JANUARY2005375

SensitivityofPersonalComputerstoVoltageSagsandShortInterruptions

´,SeniorMember,IEEE,and´,J.Desmet,Member,IEEE,G.Vanalme,J.V.MilanovicS. .Djokic

K.Stockman,StudentMember,IEEE

Abstract—Thispaperdiscussesthesensitivityofpersonalcom-puters(PCs)tovoltagesagsandshortinterruptionsonthebasisoftheextensivetestresults.Existingstandardsandpreviouslypub-lishedworksarereviewed,andadescriptionofausedtestingpro-cedureispresented.Thefollowingtestswereperformed:sensitivitytorectangularvoltagesagswithidealandnonidealsupplycharac-teristics,andsensitivitytovoltagesagscausedbythestartingoflargemotors.Theresultsobtainedemphasizetheimportanceofclearde nitionofthemalfunctioncriteriaforthisequipment.IndexTerms—Malfunctioncriterion,powerquality,shortinter-ruption,voltagesag,voltage-tolerancecurve.

Fig.1.Rectangularvoltage-tolerancecurve.

I.INTRODUCTION

ERSONALcomputer(PC)isageneral-purpose,rathercomplexelectroniccomputingdevicedesignedtobeoperatedbyonepersonatatime.Mostoften,andespeciallywhenusedasanabbreviation,thistermdenotesanIBM-com-patible(desktop)computer.Thecontinuallyincreasingratioofcomputingpowertocost,coupledwithdecreasingweight,size,andpowerconsumption,aswellastheintroductionofmoreef cientandconvenient(user-friendly)softwarein uencedboththerapiddevelopmentofPCsandextraordinarypersityoftheirusage.Today,PCsarestandard,ifnotabasicpartofscienti c,engineering,business,industrial,commercial,edu-cational,andotherenvironments,affectingalmostallaspectsoflife.

PCscanbeimplementedas“real-time”systems(i.e.,forreal-timecontrolofvariousexternaldevices),foronlinecontrolofcommunicationbetweentwoormorelocations,orasapartofcontinuousprocess-controlapplications.Suchcomputersareoftencalledmicrocontrollers,orprogrammablelogiccon-trollers(PLCs),orprogrammableelectronicdevices(PEDs).Ontheotherhand,PCscanbeusedasanoff-linetoolinsomeaction/timenoncriticalapplications(e.g.,of inecomputing,word-processing,computer-aided-design(CAD)applications,etc.).Thiscategorizationallowseasierassessmentofpossiblelossesandcostsrelatedtopower-qualitydisturbancesthatyieldtomalfunctionofPCs.MalfunctionofPCsincorporated

ManuscriptreceivedApril8,2003;revisedOctober13,2003.ThisworkwassupportedbytheU.K.’sEngineeringandPhysicalSciencesResearchCouncil(EPSRC)underGrantGR/R40265/01,theCopperDevelopmentAssociation(U.K.),andElectrotekConceptsInc.Paperno.TPWRD-00159-2003.

´andJ.V.Milanovic´arewiththeSchoolofElectricalandElec-S. .Djokic

tronicEngineering,TheUniversityofManchester,ManchesterM601QD,U.K.J.Desmet,G.Vanalme,andK.StockmanarewiththeDepartmentProvincialeIndustriëleHogeschool,HogeschoolWest-Vlaanderen,Kortrijk,Belgium.DigitalObjectIdenti er

10.1109/TPWRD.2004.837828

P

inareal-timesystemisrelatedtopotentiallybiggerconse-quences,becausetherearelossesassociatedtothecontrolledsystem/processtoo.Malfunctionoftheof ineusedcomputerisusuallyassociatedwithsubstantiallylesserconsequences(i.e.,thelossofthosepiecesofinformationgainedbetweenthelastsave/backupandthemomentofmalfunction).

ThesensitivityofPCstovoltagesagsisusuallyexpressedonlyintermsofthemagnitudeanddurationofthevoltagesag.Forthispurpose,“rectangularvoltage-tolerancecurve”showninFig.1isused.Thiscurveindicatesthatvoltagesaglongerthanthespeci eddurationanddeeperthanthespeci edvoltagemag-nitudewillleadtoamalfunction(i.e.,toarestarting/rebootingofthePC).Thereportedthresholdvaluesforvoltagemagni-tudevaryfromaslowas30–40%toashighas80–90%ofrated

inFig.1)andfromasshortas1–2cyclestoaslongvoltage

(

astencyclesfortheduration

(inFig.1)[1].

Itmaybepossible,however,thatthevoltagesag(orshortinterruption)causeslockupoftheoperationsperformedbythecomputerand/orblockageofitsoperatingsystemwithouttherestarting/rebootingofthecomputer.Thiswouldmeanthatthevoltage-tolerancecurvesobtainedusingrestarting/rebootingcriteriononlyarenotconservative.Therefore,ifonlysuchvoltage-tolerancecurveisavailable,itmaybemisleading,especiallyinthecasewhentheprocesscontrolledbythecomputerisofparticularimportanceandinterest.PCsarealreadyidenti edastheequipmentverysensitivetovariouspower-qualitydisturbancesand,therefore,theirbehaviorduringvoltagesagsandshortinterruptionsshouldbeassessedwithrespecttotheadditionalmalfunctioncriteria.

ThispapersummarizestheresultsofacomprehensivestudyofthebehaviorofPCsduringvoltagesagsandshortinterrup-tions.Afterreviewingtheexistingstandardsandpreviouslypublishedwork,thepaperpresentsextensiveexperimentalresultsthatdemonstratethatthesensitivityofPCstovoltagesagsshouldnotbeassessedonlyregardingthehardwaremal-functioncriterion(i.e.,restarting/rebootingofthecomputer).Twoadditionalsoftwaremalfunctioncriteriathatmayresultin

0885-8977/$20.00©2005IEEE

——均是精品资料,值得下载!下的越多,我越开心了。哈哈

376IEEETRANSACTIONSONPOWERDELIVERY,VOL.20,NO.1,JANUARY2005

differentvoltage-tolerancecurvesforPCswereconsideredinthetests:a)lockupofaread/writeoperation,andb)blockageoftheoperatingsystem(OS).Testswereperformedwithrectangularvoltagesagsandanidealvoltagesupply,aswellaswithnonrectangularsagsoccurringduringthestartofthelargemotors.Thein uenceofnonidealsupplycharacteristicswasalsoinvestigated.ThepaperpresentsanddiscussestheresultsoftestingofPCsonly.Theconclusionsregardingtheirbehavior,however,aretosomeextentalsoapplicabletomicro-controllers,PLCs,PEDs,andothermicroprocessor/CPU-baseddevicesthatutilizetheswitch-modepowersupply.

II.EXISTINGSTANDARDSANDPREVIOUSRESEARCHA.OverviewoftheExistingStandards

1)GeneralPowerQualityStandards:Existingpowerqualitystandards[2]–[7]de nevoltagesagsandshortin-terruptionsasashortdurationvariationofvoltageofanyorofallphasevoltagesofasingle-phaseorapolyphasepowersupplyatapointintheelectricalsystem.Althoughthereareslightdifferencesbetweenthevariousstandards,voltagesagisalw …… 此处隐藏：35510字，全部文档内容请下载后查看。喜欢就下载吧 ……