Advanced Power Electronics: Enabler for Energy Transition & Efficiency

BACKGROUND .................................................................................

APPLICATIONS OF ADVANCED POWER ELECTRONICS ..............

Smart and Sustainable Buildings ..............................................

IndustrialEnergyEfficiency.......................................................

Transportation (Land, Air, Sea) ................................................

SMART GRIDS ..................................................................................

CONCLUDING REMARKS ................................................................

REFERENCES ...................................................................................

3

4

4

7

10

12

22

23

Advanced Power Electronics | Pg 2

CONTENTS

Advanced Power Electronics | Pg 3

BACKGROUNDClimatechange is theexistential threatof today.With improving livingstandards,growth in theglobalenergydemandalongwithincreasingemissionsisinevitable.Theseseeminglycontradictorypriorities,ofincreasingeconomicgrowthvsreducingenvironmentalimpact,compelaparadigmshiftinelectricitygeneration,transmission/distribution,andefficiencyinend-use.Decouplingeconomicgrowthfromemissionswillnecessitateatransitiontowardsacarbonfreeeconomy;whichinvolvesa holistic approach towards addressing the energy trilemma of energy security, environmentalsustainability,andeconomicdevelopment.Alargeproportionoftheglobalstrategyforreductionin emissions intensity will rely on deployment of renewable energy and on energy efficiency.Theworld’sprimaryenergysupplycontinues to relyon fossil fuels (e.g.naturalgas,petroleumderivatives),withrenewables(e.g.hydropowerandsolarphotovoltaics)contributinglessthan25%totheenergymix.Encouragedbyreducingcostsofwindandsolar(viz.88%reductionincostsfrom2001to2019),investmentsinrenewablescontinuestooutstripinvestmentsinnewcapacityoffossilfuelbasedpowergenerationplants.Asignificantreductioninthecostsofbatteries(viz.86%from2010to2019)hasalsoenabledoptimismthattheintermittencyofrenewables(viz.solarcellsdonotgenerateelectricityundercloudyconditionsoratnight)canbebufferedbybatteries.

Energyefficiency–thekilowatt-hoursweavoidbyeliminatingwaste–isbyfartheworld’slowest-cost resource.Energy efficiencymeasures comprise of employing themost efficientmeans ofelectricity generation and reducing losses in electrical power systems. Final energy demanddelivered by electricity (e.g. transportation, cooking, cooling) will double from 19% in 2017 to40%in2050;makingelectricitythefastestgrowingformofend-useenergy.Functionsofcontrol,conversion (e.g. high voltage to low voltage), transmission and distribution can be fulfilled byanalog devices (e.g. conventional transformers) or through use of electronic components, viz.power electronics. Power electronics include semiconductor devices that function as switchesin electrical systems, and are responsible for controlling the flow of electrical energy from thesource to load.Powerelectronicsenableextremelyefficientconversionofelectricalpowerandalsocanprovideoptimalconditionsforintegratingdistributedgeneration.Becauseoftheirpotentialto enable digitalization, and their highly efficient operations, it is estimated that the amount ofelectricityprocessedbypowerelectroniccomponentswilldoubleoverthenextdecade,reachingup to 80% by 2030. Power electronics components used today are based on silicon (Si) andincludemetaloxidefieldeffecttransistors(MOSFET),InsulatedGateBipolarTransistor(IGBTs),and thyristors.There are few limitations ofSi based devices,which include - high losses, lowswitchingfrequencies,lowthermalconductivity,andpoorperformanceattemperatures>125oC.Materialssuchassiliconcarbide(SiC)andgalliumnitride(GaN)haveagreatpotentialtoovercomethe limitationsofSi,andas they transit fromresearchanddevelopment tocommerciallyviableproducts,theyaredrivingenergyefficiencyandperformancegainsinpowerelectronicsystems.

Figure 1: Potential energy savings

ThereducedlossesasshowninFigure1areattributabletomaterialpropertiesofSiCsuchashighbreakdownstrengthcoupledwithreasonablyhighelectricalandthermalconductivity.Thesematerialpropertiesdeliverimprovedefficiency,savingsoncoolingrequirements,improvedsignal/ noise ratios, and miniaturization due to increased switching frequencies. Advanced powerelectronicsviz.SiCandGaNarethuskeyenablersforefficientgeneration,distribution,anduseofelectricalenergy.Itisestimatedthattheseadvancedpowerelectronicscouldreduceenergylossesinelectronicequipmentbymorethan50%.Domainswherepowerelectronicsareenvisagedtomakemajor impact include electric motor drives, electric mobility, home appliances, industrialapplications,datacentres,lighting,intelligentbuildings,andsmartgrids.

AppliCATiONS Of ADvANCED pOwER ElECTRONiCSApplicationsofadvancedpowerelectronicscanbebroadlygroupedunderthefourcategoriesof:Smart&SustainableBuildings,IndustrialEnergyEfficiency,Transportation(Land,Air,Sea),andSmartGrids.Advancedpowerelectronicsisthetechnologybehindthekeyimplementeroflow-energyconsumptionideas.Powerelectronicsenablesthisbyvariousmeanswherethemostnotableamongthemaretoenableoperationofthesystemsatclosetounitypowerfactorofoperation,andoperationattheload’scustomisedvoltagelevelaswellasfrequencythusensuringthatthesystemoperatesatoptimalenergyequilibrium.Withintelligentandsmartelectronicmonitoringandcontrol,thesystemrespondstoloadsmuchfasterandclosertooptimumoperationsthansystemsthatdonotemploypowerelectronics.

Smart and Sustainable BuildingsThebuildingsectoraccountsforapproximatelyone-thirdofSingapore’selectricityconsumption.The BuildingConstructionAuthority (BCA) Singapore defines Zero Energy Buildings (ZEB) asthosewhogeneratealloftheirenergyneeds(includingplugloads)fromrenewablesourcesandSuperLowEnergyBuildings(SLEB)needtodemonstrateatleast60%energysavings(comparedto2005levels).Beforeanygainsfromrenewablesareconsidered,thebuildingsneedtoconsiderenergyefficiencymeasuresthatincludesunlightshading,dynamicfacades,airconditioningandmechanicalventilation(ACMV),lighting,buildingautomation,plugloadmanagement,buildingtogrid integration,andotheroptionsinpassivedesign(e.g.naturalventilation).Powerelectronicsare key enablers of all energy efficiency areas listed here, excluding those of passive designbasedmeasures.Otheradvancedstrategiesincludesmartdevicesthatnotonlymetertheenergyconsumed but also provide real-time information, incentive pricing, deviations from standardconsumption etc., to help people living in ormanaging these environments save energywhilemaintainingthedesiredcomfort levels.Decentralisedmonitoringandcontrolsystemsforpowerquality management, communication protocols, e-trading platforms for dynamic pricing, virtualpower plant and service architectures constitute developments that will also see widespreadimplementation inthenearfuture.Besiderenewables,on-siteenergystorage(e.g.batteries,orstorageofice/coldwaterforchillersystemsinbuildings)andenergystorageinelectricvehicles(EV)canfacilitatestabilisationofpowersupplyandalsoprovideamechanismtomanagepeakdemand.

Advanced Power Electronics | Pg 4

Thecritical technologiesforsmartandsustainablebuildingsincludesolidstatelighting,heating,ventilation,andair-conditioning(HVAC),andintelligentcontrolsystemsforbuildingmanagement.In the buildings area, power electronics plays a critical role for actuation, and control. HVACsystemsgettheircontrolsthroughelectricmotordrivescontrolledbypowerelectronics.Lightingsystemscannothaveadaptivecontrolswithoutpowerelectronics.Anyautomatedmanagementofsafetysystems,elevators,watermanagement,andbuildinguserunsonmodernadvancedpowerelectronics.Approximately25%oftotalelectricalenergyisconsumedbylighting.Savingsof70%-90%canbeachieved through theuseof solid state lightingwithelectronicballasts, dynamicdimming controlled by adaptive sensors thatmeasure occupancy / natural lighting, and higherefficiencypowersuppliesthatcontroltheindividualLEDs.Heating,ventilationandairconditioning(HVAC)accountsforabout56%intropicalareasandabout40%ofthetotalenergyconsumptioninbuildings,includingelectricalandnon-electricalheating/coolinginregionslikeUSandAustralia.Using advanced control together with energy-efficient appliances based on advanced powerelectronics, it ispossibletosavearound20%oftotalenergyconsumptionbothinelectricalandnon-electricalsystems.InSingapore,buildingsaccountfor31%ofthetotalenergyconsumptionHouseholdsandbuildingloadstogetherformthelargestusersofenergy.

Heating,ventilationandairconditioning(HVAC)accountsfor70%ofthetotalenergyconsumptioninbuildings,includingelectricalandnon-electricalheating/cooling.Lightingloadshaveimprovedspecially for the new buildings but are still responsible for 15%of the total energy consumed.Most residential and commercial buildings deploy lifts and escalators that are designed usingconventionaltechnologyinwhichenergysavingswasnotthemainguidingfactor.Theysufferfromgraduallyfallingefficienciesandaccountformorethan10%oftheenergyconsumedinbuildings.Singapore’stropicalclimatechallengestheclassicalmethodsofachievinghighenergyefficiencies,andnewapproachesareneededtocreateasustainableimpact.Variousapproacheshavebeenrecommended in the “super lowenergy” technology roadmapby thebuildingsandconstructionauthority(BCA)whichaimstoachieveNetzeroenergyconsumptioninbuildings.Theapproachesconsiderpassivestrategies,(Figure2)inwhichbuildingdesignformsthekeyfocus.Newbuildingshavestartedadoptingmethods inwhichbothbuilding thermalmanagementand lightingwillbedesignedinmorecreativewayssothatnatural lightandventilationcanreducetheneedtouseelectricalenergyforthepurpose.Whilesuchpassiveapproachesofbuildingandcampusdesignswillworkforthenewinstallations,theexistingones(whichformthemajorityofthebuildingsload)can benefit from activelymanaging and controlling the air-conditioning, ventilation and lightingloads.

Smartandmodularbuildingenergymanagementsystemsthatareeithercustombuiltorwillbemadetospecificstandardsareproposedasanimportantapproachtoreduceenergyconsumptioninexistingandnewbuildings.Usingadvancedcontroltogetherwithenergy-efficientappliancesbasedonadvancedpowerelectronics,itispossibletosavemorethan30%oftotalenergyconsumptionbothinelectricalandnon-electricalHVAC.ReplacingallthemotorsandpumpsintheHVACelectricsystems by higher-efficiency ones, including external continuous control, variable speed drivesbased on power electronics and using intelligent control forHVACand the environmental datagatheredbywireless sensors, theenergyefficiencyof a complete systemcanbe improvedby30–40%.Approximately 25% of total electrical energy is consumed by lighting; and significantsavingscanbeachievedthroughtheuseofsolidstatelighting,coupledwithelectronicandsmartcontrols.By replacing hydraulic liftswith electric traction lifts using advance power electronics-basedspeedcontrol,feedbackandlowconsumptionstand-bymode(~80%ofalift’sannualenergyconsumption), one can achieve savings of over 50%.These energy efficientmeasures reduceenergyconsumptionbybetween50and75%.Escalators formanessential load incommercialbuildings.Withadvancedpowerelectronicconversion,highlyefficientelectricmotorscanbeusedinavariablevoltagevariablefrequency(VVVF)controlmode.

Advanced Power Electronics | Pg 5

Figure 2: Advanced power electronics will enable buildings to achieve net zero in energy consumption (Source: Building and Construction Authority Singapore)

Escalatorspeedscanbevariedaccordingtothepassengerloadandseamlesslyautomaticstart/stopcontrolorvariable-speedcontrolscanbeimplemented.Inidleconditionsofnopassengerorlowpassengernumbers,significantenergysavingscanbeachievedwiththisapproach.Additionally,integrationof theroof-topsolar inbuildingshasbeenagrowingpractice in tropicalmega-cities.Forsustainablenetzero(peryear)inabuilding,it ispossibletoestimatetherenewableenergycontributionbasedonthelocationandweatheratthatplace.Thisdataisindicativeoftheextentofothermeasureslike“activestrategies”and“smartenergymanagement”requiredtoachieveanetzeroperyear.Advancedpowerelectronicsenablesmulti-functionalinterfacedevicestomaximiseenergycapture.Togetherwithenergysavingmeasures,thiswillplayasignificantroleinachievingnetzeroinbuildingenergyconsumption.

Globally,therehasbeenashifttowardsenergyefficientbuildingtechnologiesmentionedabove.In the USA for instance, there are efforts towards investigating smart alternating current (AC)nanogridsfortoday’stechnologyanddirectcurrent(DC)nanogridsforsmart,sustainablehomesandbuildingsof tomorrow.TheACnanogrids incorporatesmartappliances, lightingandHVACwithon-sitepowergenerationandanEnergyControlCentre(ECC).TheECCcancommunicatewiththepowersystemoperatorforenergytradingpurposes,whilealsoactingasadataacquisitionunit.TheECCcancollectandrecordthepowerflowdatanotonlyfromandtowardsthegrid,butalsofromalltheconvertersandsmartappliancesinthehome.Industrieshavealsoalignedtheirproductsaroundgreenandenergyefficientbuildingswith theobjectivesof improvedefficiency,greenerfootprintfromrenewablesandenergymanagement.

Another important aspect is the reactive power, which is that part of the power that does notparticipateinactiveworkdone,butaidsinstabilisingvoltage,andisanintegralrequirementforthegrid.Thisiscriticalinresidentialandmoresoindustrialunits,asthemotors,whichperformmostwork, need inductive reactive current formagnetisation.This required reactive current is eithersuppliedbymeansofpassiveorpowerelectronicsbasedactivemeans.ThepotentialadvancedloadsandinterconnectioninbuildingenvironmentcanberepresentedasgiveninFigure3.

DCdistributioninbuildingsisanotherareathatisbeingresearchedinSingaporeandglobally.Inhighperformancebuildings,mostloads(e.g.laptops,LEDs)havepowersupplies/convertersthatconvertACsupplytoDCcurrents.Electricalpowerstorageandsolarpowergeneration,whicharebothgrowingatunprecedentedrates,deliverpowerthroughDC.Mostofourelectricalappliances,bothathomeandattheoffice,alsouseDC.Still,becausethepowergridsuppliesACpowertohouseholds,electricityfrombatterystoragesorPVhastobeconvertedtoACandthenbacktoDCbeforeitcanbeusedinhouseholdsorofficebuildings.

Advanced Power Electronics | Pg 6

Figure 3: Smart Building and City

While high-endAC/DC converters used for battery storage and PV typically lose 3-6% of theelectricityintheconversion,standardconsumerelectronicconvertersandLED-drivershavelossesofupto25%.A“direct-DC”buildingdistributionsystemwithonsitePVandDCappliancescouldbetweensave5-15%energybyavoidingpowerconversionlossesfromDCtoACandbacktoDC.

Industrial Energy Efficiency Efficiencyisapowerfuldrivingforceinallindustries,asinefficiencyoftentranslatesintounnecessarilyhighcosts.Themannerinwhichindustrialsystemsarepoweredischangingdramaticallyasthedemandforpowerincreasesand,atthesametime,asenvironmental,commercial,andlegislativepressuremountstoreduceenergyconsumptionandincreaseenergyefficiencies.Theindustrialsectoracrosstheglobe,usesupto50%oftheusefuldeliveredenergy.Energysavingsintherangeof30%–50%couldberealisedwiththeuseofefficientmotorsystemswithvariablespeeddrivesusingadvancedpowerelectronics.Thefourthindustrialrevolution(orIndustry4.0)isexpectedtobehighlyefficientwithacyber-physicalsystemtomonitorthephysicalprocessesofthefactorywithallprogrammedandartificialintelligence(AI)baseddecisionmakingalgorithms.

For this tobea reality,smartandconnected factoriesmandateanewandbetterapproach forpowering them.Advanced power electronics plays a crucial part here when a high voltage isconverted toa lowervoltage,withminimalenergy lossduring theconversion.Advancedpowerelectronicsreducessuchenergylossesby(1)minimisingthenumberoftimesthatavoltagemustbeconverted,and(2)decreasingtheinefficienciesduringsuchvoltageconversions.Approximately65%oftheelectricityusebyindustryisusedtodriveelectricmotorsystems.UseofVariableSpeedDrives(VSDs),HighEfficiencyMotors(HEMs),efficientpumps,compressorsandfanscaneachachieveenergysavingsofupto40%asperestimations,andcouldtranslateintooverallenergysavingsintherangeof30-40%,withpaybackperiodsof2-3years,andaCO2reductionpotentialof~25%.SuchenhancedefficienciesareachievedthroughtheseamlesscontrolofcompressorfunctionsratherthananONandOFFswitching.

Advanced Power Electronics | Pg 7

Industrialmotorsmainlyarethosethatfindapplicationinelevators,refrigerators,airconditioners,washingmachinesandfactories.Thevastmajorityofthesemotorsdonothaveelectroniccontrols.Electricmotion(motionexcludingtransportation)accountsfor80QBtu(0.02kWh).Simpleelectricmotors (without intelligentcontrolelectronics)account forabout70QBtu.Thesesimpleelectricmotorsareeitherfullyonorfullyoff,whichislikedrivingwiththeacceleratorpushedallthewaytothefloorthentakingitoff,overandoveragain.Besidesthisbeingapoorwaytodrive,italsoturnsouttobelessefficient.Byconvertingallsuchsimpleelectricmotorstovariablespeeddrives(VSD),it ispossible tocutpowerconsumptionbyalmosthalf,asshown inFigure4.Similargainsareachievableinair-conditionersusingVSDbyusingseamlesspowerelectronicscontrol,comparedto conventional controllers that leads to oscillations and slow response as shown in Figure 5.Thereisanadditionalenergysavingof20%throughtherecuperationofelectricalmachinesduringbreaking,whichisfrequentlyusedinelevatorsandtractionapplicationoftrainsandheavyvehicleswithpowerelectronicconverters.

Figure 4: VSDs based improved energy savings

Figure 5: Variable speed drive in air-con

Advanced Power Electronics | Pg 8

The energy use by data centres grew by awhopping 90%between 2000 and 2005 and 24%between2005and2010.What’smoreimpressiveis,thatbetween2014and2020,thedatacentreenergyuseincreasedagainbyonly4%(8).Thismassiveenergysavingsaccomplishmentoccurredduetotheeffortsofgiantinternetcompanies(suchasGoogle,Amazon,andFacebook)tostayfocusedonmakingtheirdatacentresoperatemoreefficiently.

Suchmassivegainswereachievedmainlyduetoinnovativeenergymanagementmeansincludingenergy-efficiency software,automatically switching toa low-power stateat lowutilisation rates,outdooraircooling,andadvancedpowerelectronics.PowerdistributiontoITequipmentinadatacentreisaccomplishedusingACorDCpower.ACpowerisdistributedatthevoltageof120V,208V,or230V.DCpoweristypicallydistributedatthetelecommunicationsstandardvoltageof48V.MostexistinginstallationsuseACdistribution;however,theuseofDCpowerisgaininginterestsinceit improveselectricalefficiencywhensomestepsofpowerconversionsareeliminated,resultinginreducedlosses.TypicaldatacentrepowerdistributionisshowninFigure6,wheremanyofthecomponentsinsuchACdistributionincludingdoubleconversionUPSandPDUcanberemovedifthedistributionplatformisDC.

Figure 6: Typical Data Centre power distribution using AC

Thevariousadvantagesofusingadvancedpowerelectronics&DCpower includefewerpowerconversionstages,smallercablesizes,improvedredundancythroughdistributedenergystorage,reducedcomponentcounts,andreducedspacerequirementsprovidingmoreserverareaspaceforactualenduse.

Advanced Power Electronics | Pg 9

Transportation (land, Air, Sea)Transportationasawholeisestimatedtoberesponsibleforover20%oftheworld’sCO2discharges,withaviationandshippingcontributing2%&3%respectively,androadtransportcontributingtotherest.Electrificationofroadtransport,andmoreelectricaircraftsaswellasshipsareconsideredto be very significant opportunities for emissions reduction.Application of power electronics inautomotiveapplicationsplaysamajorroleincontrollingautomotiveelectronicsincludingmodernelectricpowersteering,main inverter,centralbodycontrol,brakingsystem,seatcontroletc.,asshownbelow(Figure7).

Figure 7: Power electronics in automotive applications

Applicationofpowerelectronicsintheautomotivepowergenerationsystemprovidesautomotivealternators with improved efficiency and high power, along with high temperature withstandingcapacityandhigh-powerdensity.Thereisavarietyofresearchindesigningalternatorswithswitchedmodepowerelectronicsapplications.Powerelectronicsfindsapplications in fourmainareasofhybridpowertrains:Regenerativebraking(AC/DCconversion),On-boardcharger(AC/DC),Dualbatterysystemandcontrol (DC/DC),andTractionmotor (DC/AC).TheHV-LVDC-DCconvertershown inFigure7supplies the12Vpowersystemfromthehighvoltagebattery.Theon-boardchargerhelpstochargethebatteryinEVusingastandardpoweroutlet.Themainperformancefactors of these power converters involve efficiency and a high power density for a small formfactor.Thefuturedesigntrendistowardsanadvancedbi-directionalchargingcapability,wherethechargerfeedspowerfromthebatterybacktothegrid.

RecentyearshavewitnessedincreasingprogressinthedesignofhighperformancecontrollersforACmotors.Still,thepowerstoredinthebattery(HEV/EV)orfueledbypetrolmustbeconvertedfromDCtoACinordertorunACmotors.Mostcommerciallyavailableautomotivepowerconvertersusesilicon(Si)basedsemiconductordevicesasswitches.Thepowerconvertercontrolsturnon/offtheSiswitchessothattheoutputvoltagewaveformsmeetthedesiredtype(DCorAC),magnitudeandfrequency(typicallyforACitis50/60Hz).BasedonhowfasttheSidevicescanbecycledonandoffandthepowerconvertertopology,thequalityoftheoutputwaveformcanbeverydifferent.CurrentlySidevicesusedforhighpowerapplications(~100kW-MW)cannotbeturnedonoroffatafastrate(notbeyondfewkHz).Theswitchingfrequencyislimitedbecauseofhighlossesassociatedwith increased switching, and delayed turn off results in high voltageswhichmay damage thesemiconductordevices.Thus,mostSibasedconvertersareoperatedatlowerfrequenciesresultinginoutputvoltagewaveformswithhigherharmonicsandnoisecontent.

Advanced Power Electronics | Pg 10

Inordertoreducetheseharmonicdistortionstoacceptablelevels,largefilterswithhugeinductorsandcapacitorsareused.Sincefiltersare rated forhighpower, there issignificantfilter loss, inadditiontotheSideviceconductionandswitchinglosses.Thislowerstheefficiencyandescalatesthe need for extensive cooling system to manage the operating temperature of the devices.Additionally,inautomotiveapplications,theexternalenvironmentisveryharshthatmakescoolingevenmorecomplexandbulky.ToavoidSidevicesfromgettingdamaged,itisnecessarytoensurethat theconverteroperating temperature isalwaysbelow125°C.Largeheat sinks,bulkyfiltersandextensivecoolingsystemsfurtherincreasetheweightandsize.Thewidebandgapdevices,specificallySiliconCarbide(SiC)andGalliumNitrite(GaN),havebeenusedforseveralyearsinRadioFrequency(RF)applications,andlowpowerapplications.Recently,several investigationswereundertakentoexploretheirutilityinhighpowerapplicationslikeelectriccarchargers,electricdrive trainpowerelectronics,etc.Thesenewdevicescould revolutionize theway inwhichhighpowerconvertersaredesignedandbuilt.ThemanyadvantagesofadvancedpowerelectronicsbasedonSICarecaptured inFigure8, including improvedefficiency,sizereductionandhigherpowerdensity.

AdvancedPowerElectronicsistheenablingtechnologythatmakesthisprocesspossibleandmoreefficient.AHighVoltage(HV)DClinerunsfromthebatterytothesub-systemsandthecomponentsoftheHEVsystem.Aninverterwillconvertdirectcurrent(DC)fromthecar’sbatteriestoalternatingcurrent(AC)todrivetheelectric(traction)motorthatprovidespowertothewheels.TheinverteralsoconvertsACtoDCwhenittakespowerfromthegeneratortorechargethebatteries.Inthetransportationcontext,theyfindapplicationsinchargersanddrivetrainapplicationsforhybridandfullyelectriccars.Inhighfrequencychargers,itcouldreducethechargerfootprint,lowerparasitic&switchinglosses,andleadtofastchargerdesigns.Fordrivetrains,GaNdevicesmaynotscaleuptothevoltageandpowerlevelsneededfordrivetrainconvertersandSiCmaybeabetterchoice.Thesedevicescouldalsofindapplications inaircrafts, shipsandelectric trainpowerelectronicconverters.ThefutureofusingGaNandSiCdevicesintransportationelectrificationseemstobeverypromisingduetotheclearadvantages,likelowerlossesandsmallerfootprint.However,torealisetheseadvantagesinpractice,researchanddevelopment(R&D)isrequiredtospecificallyaddressimprovementinsystemsreliabilityandefficientdevicepackaging.

Figure 8: Benefits of advanced power electronics in automotive segment

PowerelectronicsR&DinDCfastchargingishelpingtheEVindustrytotakethechargeroutofsomevehiclesandputitoffboardforsomedrivingapplications.Thisspaceconstraintofanon-boardchargeralongwiththetimetochargewhichrangesfrom4-5hoursisthemotivationfactorfortheresearchandproductdevelopmentinDCfastchargers.TypicalchargingsystemsfortheAClevel2,DCfastchargingandwirelesscharging,whicharerecentlygettingpopularfortheeaseofchargingareshowninFigure9.

Advanced Power Electronics | Pg 11

DCFastChargingbypassesallthelimitationsoftheon-boardchargerandrequiredconversion,andinsteadprovideDCpowerdirectlytothebattery,whichhasthepotentialtosignificantlyincreasethechargingspeed.DCfastchargerscanprovideupto400kWofDCoutputpower(typicallyfrom400VDCto1000VDC),convertingthree-phaseACpowersourcedfromtheelectricalgridintoDCpowerusinghighlyefficientpowersemiconductordevices.

Thishighoutputpowercanchargefullydepletedbatteriesonmostvehiclesto80%oftheirfullchargeinmaximum30minutes.ThechargingtimeisadirectfunctionoftheDCchargingvoltageandthepoweroutput.Therelationisalmostlinearbetweenthetradeoffofhigherpowertochargingtime.Ifa50kWchargertypicallytakesabout50minschargingtime,a350kWchargerroughlytakes1/7ththe time.TypicalofsuchDCfastchargerswouldbebuck-boostdc-dcconverterwithcontrolledpre-chargingoftheHVDClinkandintelligentpowerandbatteryenergymanagement.Alongwiththis,thevoltagerangeofDCbusintherangeof600V–1000Venableseasyinterconnectionwiththegridthroughabi-directionalinvertertoaidpowerflowfromEVtogridforimprovingitsdynamicstability.ThefutureroadmapforEVChargersystemsis tobringdownthatchargingtimetothesametimeasfillingatraditionalvehicle’sgastank.Thelargerthesizeoftheelectricmotorandtheenergystoragesystem,thehigherthefunctionalityandfuelefficiency(FE)benefit.OneprocessthatiscommonacrossalltheHEVsystemsistheconversion,storageandlaterusageofenergy.AdvancedPowerElectronicsistheenablingtechnologythatmakesthisprocesspossibleandmoreefficient.

Figure 9: AC level 2 and DC fast charging system structures

HighVoltage(HV)DClinerunsfromthebatterytothesub-systemsandthecomponentsoftheHEVsystem.Aninverterwillconvertdirectcurrent(DC)fromthecar’sbatteriestoalternatingcurrent(AC)todrivetheelectric(traction)motorthatprovidespowertothewheels.TheinverteralsoconvertsAC toDCwhen it takes power from the generator to recharge the batteries.Advanced powerelectronicsplaysakeyroleinredesigningaircraftsanddevelopingfullyelectricplanes.Advantagesofelectricaircraftandmoreelectricaircraft(MEA), includeimprovedmanoeuvrabilityduetothegreater torque from electric motors, increased safety due to decreased chance of mechanicalfailure, less riskofexplosionor fire in theeventofa collision,and lessnoise.Therewouldbeenvironmentalandcostbenefitsassociatedwiththeeliminationofconsumptionoffossilfuelsandresultantemissions.Inaerospacesystems,powerelectronicrelatedintegrationissuesare-thelevelofpowerandmissiondependenthightemperatureranges,weightandsize,electromagneticinterferenceandhighperformance.ResolutionoftheseissuesarecriticalforfurtherprogressinMEA.A schematic representation ofMEA is shown in Figure 10. The concept to drive aircraftsubsystemswithelectricalpowerinlieuofmechanical,hydraulicandpneumaticmeansistheMoreElectricaircraft.Theendobjectivewastoeliminatetheneedforgearboxes.

Advanced Power Electronics | Pg 12

Figure 10: Conventional Vs More electric aircraft

Powerelectronicsprovidesthemeanstoconvertelectricalpowertodrivemotordrivenactuators,fuelpumpsandothersubsystemsatvariablespeed.AtypicalMEAhasthecomponentscontrolledthroughvariouspowerelectronicmodulesusedwithPVarrays,batteryandbatterychargeanddischarge control units (BCCM, BDCM), low voltage convertermodules (LVCM) and themainpowerdistributionunit (PDU).Shipping facilitatesaround90percentof theworld trade.Facingtightenvironmentalregulations,theshippingoperatorsandportauthoritieshavetolookforwaystoreduceemissionandnoiselevels.Inthemajorityofports,shipsatberthusetheirdieselgeneratorsto runamenities suchasheating, ventilation, coolingaswell asgalley equipment.Becauseofthat,theyproducenoxiousemissionswhichhaveanegativeimpactnotonlyonthesurroundingenvironment,butalsoontheglobalclimate.

At the same time noise and vibrations from ships seriously affect the life quality of the localcommunities.Additionally,mostships’powergenerationunitsoperateata frequencyof60Hz,whereaslocalgridinmostpartsoftheworldis50Hz.Thismeansthatprovidingshipswithelectricityrequires a shore-side electricity supply arrangement.Advancedpower electronics basedStaticFrequencyConverters(SFCs),providethemeansforasafe,economicandhighlyefficientsolutiontoconvertthegridelectricitytotheappropriateloadfrequency.Theshore-to-shipelectricpowersupply,alsoknownascoldironing,isthemostreasonableandcost-effectivechoiceforgreenerportsandfleet.Thesolutionenablesships toshutdown theirdieselgeneratorsused tocreateonboardelectricpowerandplugintoanonshorepowersourcewhileberthed.Theleading-edgefrequencyconversion technologyguaranteesaseamlessautomatedpower transferof theshiploadfromtheonboardpowerplanttotheonshoresourceandback.

Thiscontributes toasignificant reductionof fueland lubricationoil consumption,whichmeanslesspollutionandexpenditure.Shore-to-shippowerisespeciallyapplicabletoshipsoperatingondedicatedroutesandvesselsthatconsumelargeamountsofpowerwhileinport.Thiscouldbringrealbenefitsfor terminaloperatorswhoseferriesberthdaily forafixednumberofhours.Shorepowerorshoresupply is thedeliveryofshoresideelectricalpower toashipatberthwhile itsmainandauxiliaryenginesareturnedoff.Theobjectiveistoprovideasystemincludingapowerconverter forconvertingshorepower toshipboardusewhich iseasy touseandcosteffective.SuchasolutionisdepictedinFigure11,wheretheelectricityfromshoreisusedtopowerauxiliaryservicesoftheshipatberthandismoreenvironmentallyfriendlycomparedtodieselsets.Insuchasystem,apowerelectronicsconverterisused,whichcanconvertshorepowertoshipboarduseandalso transfer theship’smainpowerdistribution to theACshorepowerwithout interruptingpowertovariousshipboardelectricalcomponents.

Advanced Power Electronics | Pg 13

Figure 11: Shore power system based on power electronics

Theprimaryobjectiveoftheshorepowersystemistoprovidepowerconverterforconvertingshorepower(atshorefrequencyandvoltage)toshipboarduse(atshiprequiredfrequencyandvoltage)andtotransfertheship’sloadfromonepowerpathtoanotherwithoutinterruptingpowertovariousshipboardelectricalcomponentsandwhichcanbeusedinportsaroundtheworld.

In termsof on-board shipelectric distribution system,DCpowerdistribution in ships is gainingattention.DCbasedgridpowersystemhasfollowingbenefitscomparedtotheAC-gridintermsofthepowerstabilityandqualityaspect.

• Freedomofthereactivepower(increasingpowerstability)• Freedomofthefrequency(easysynchronisingofpowersources)• DC-basedpowerdistribution(reducingharmonicdistortionsandincreasingpowerquality)

In addition, it is effortless to integrateDCpower sources (e.g., fuel cells, lithium–ion batteries,supercapacitors, etc.) into aDC-bus. Especially, theESS could be used for various purposes:peakshaving, load levelling,absorbingregenerativepower,etc.Therefore, theESScanreducegensets’runningtimeandimproveenergyefficiency.Besides,itcanalsocontributetoreducingthemaintenancecostofgensets.SimilartoMEA,moreelectricships(MES),areenabledbythevariousimprovements inpowerelectronics for enablinghigh voltageandalsopossibleDCdistribution.Hybridelectricandfullyelectricshipsareslowlyontheriseduetoseveraladvantagesincludingreductionofemissions.

Inhybridsystems,theelectricityisderivedfromdieselgeneratorsandbatteries.Withhigherdenseenergystoragesystems,andadvancedPE,theconversionefficiencyismovinghigheralongwiththepossibilityofDCdistributionenabledbyhigherenergyefficientarchitectures.PEdrivenvariablespeeddriveshavealsobecomeefficientfrombothconverterandmotorperspectives,advancedbySiCdevices,PMmotorsandhighfrequencyelectromagnetics.WithsuchDCbasedsystems,thepresenttransformerbasedACinterfacecanberemoved.Withhighvoltagepowerconversion,thestepdowngearcanberemovedandthegeneratorcanbedirectlyintegratedwiththeprimemovertooperateatthesamespeed.WithincreasedvoltageusingSiC,atthesamepowerlevel,theMEScanbedesignedforreducedweight,sizeandcost.

SmART GRiDSAlternatingCurrent(AC)hasbeentheconduittotransferelectricalenergyfrompowerplantstoallkindsofindustrialandhouseholdloads.Conventionally,thismechanismhasbeenwellunderstoodandadaptedworldwide.Theunidirectionalpowerflowarchitecturethatdirectselectricalenergytoflowfromgeneratingpowerstationstoloadhasremainedalmostunchangedforoveracenturyormore.However,recentglobalawarenessregardingclimatechangeandsharpreductionincostsof renewables (e.g. solar andwind) and energy storage (e.g. lithium ion batteries) have led toincreasing renewable energy sources being connected to the network in a distributedmanner.Greener technologies for more efficient power generation, distribution and delivery in differentsectorsarealsospreadingasaresponsetotheneedformitigationmeasuresforclimatechange.

Globally,5.9TWhofrenewableenergywasproducedintheyear2016,representinga5to6-foldincreasesince1960s.Renewableenergygrowthisexpectedtoincreasefurtherinthenearfutureto36%oftotalenergyshareby2030andto65%oftotalenergyshareby2050.Electriccarsalesareprojectedtobypassinternalcombustionenginecarsby2030.Inadditiontothesedistributedsources of generation and loads, recent years have also seen a very significant advance ofdigital technologies.Theseadvancesincludesmartmeters,communicationsnetworks,anddatamanagementsystemsthatenabletwo-waycommunicationbetweenutilitiesandcustomers.Bettermonitoring and control have enhanced both energy efficiency and reliability. The conventionalPowerGridisthusmigratingtothatSmartGrid,whichmaybeviewedasanelectricitynetworkthatenablesintegrationofrenewablesandusessmarttechnologiestobetterserveconsumers.

WhiletheSmartGridoffersaverysignificantadvanceover theconventionalpowergrid, itskeylimitationisthatalthoughtheflowofcommunicationsisbi-directional,theflowofenergyremainsunidirectional.Withtheconfluenceofrenewables,energystorageanddistributedloads(e.g.electriccars),thegridcannolongeroperatewiththeconventionalideaofunidirectionalpowerflowandbothgenerationandconsumptionwillbecarriedoutatmultiplenodesofthenetwork.Itneedsaradicalchangetoaccommodatesuchrenewableenergysourceswhichcanbeintegratedatanypointofthetransmission&/ordistributionnetwork.TheSmartGrid2.0(SG2.0)isenvisionedtobeatechnologyleapthatwillusherintheInternetofEnergy(Figure12),withthecapabilitytomanagemillionsofconnecteddevicesatalllevelsofthegrid.Seamlessconnectivityandon-demandenergyroutingwillreplacetheconventionalunidirectionalflowofenergy.Themodernisationofsoftcomponents involvesadvanceddigital informationandtelecommunication technologies.SG2.0willbesmarterbecauseof itsability tophysically routeand control various formsof energies anddifferent pockets of generation to the ever-changingnatureofconnectedloads.Suchloadshaveevolvedovertimeandhavebeenembracedgloballybecauseof the immensepotentialofoverallenergyefficiency in theoffer. Tobeabletorapidlycommunicate, enabled by evolving power electronics, has been at the heart of this disruptivetechnological breakthrough that facilitates a paradigm shift in the energy economy. Integrationoffastcommunicationandrapidroutingofenergythroughelectroniccircuitswillallowcontrolledenergymanagementandpowerregulation.PowerelectronicswillremainoneofthemostcrucialandevolvingbranchesofSmartGridsandSG2.0powerindustryoverthenextcentury.

Figure 12: Conventional Grid vs Smart Grid vs Smart Grid 2.0. Smart Grid enables bi-directional information flow (red dotted line), Smart Grid 2.0 enables bi-directional flow of both energy and information (blue arrows)

Advanced Power Electronics | Pg 16

The latest powerelectronicsmarket forecastsan increaseof 60% for low-voltage technologies(below 900 V) by the year 2020, accompanied by an approximately 100% market increaseformedium (1.2–1.7 kV) and high voltage (2 kV and above) technologies (Lacopi, 2015). Thepowerelectronicsrevolutionhascreatedabaseforaworldrigorouslyworking towardsgreenertechnologies:improvedenergyconversionefficiencies,fasterswitching,morecompact,andlightersystemswithbetterthermalmanagement.SmartGridofferscontrolofpowerthatplaysanimportantroleinmodernindustrialautomationandhigh-efficiencyenergynetworkthatincludesrenewableenergysystems(viz.photovoltaics,windenergy),bulkenergystorage,electricaswellashybridvehicles,andenergy-efficiencyimprovementofexistingelectricalequipage.

In modern electric power grid, power electronics is vital in high-voltage DC (HVDC) systems,staticVAR(Volt-AmpereReactive)powercompensators(SVCs),flexibleACtransmissionsystem(FACTS)-basedactiveandreactivepowerflowcontrol,anduninterruptiblepowersystem(UPS)tonamea few.HVDCprovides longdistance, low-loss transmission (vsAC transmission), andFACTS(FlexibleACTransmissionsystems),whichincludesthefamilyofcontrollablehighpowerdevices(viz.SVC,staticcompensatororSTATCOM),andenablesimproved,morestable&moreeconomicalutilisationofpowersystems.

On the other hand, SVCs are beneficial for increased power transfer capability bymaintainingastablevoltageprofileunderdifferentnetworkand loadconditions, thereby improvingdynamicstabilityofthegrid.PowerelectronicsfortheseapplicationshavebeenmainlybasedonThyristorsandIGBTs.However,recentlyadvancedpowerelectronicsbasedonSiCaregainingpopularityduetovariousbenefitsincludingbetterpowerdensityandsystemefficiency.Allofthesecomponents/ sub-systems (e.g.FACTs,STATCOMs,voltage /power transfer&powerflowconverters,andcompensators)bringthefollowingbenefitstoSmartGrids:

• Improvedpowerquality• Compliancetogridcodesofvariouscountries• Gridvoltagestabilisation• Improvedpowertransfercapability,includingthoseofexistingassets• Steady-stateanddynamicreactivepowercompensationandvoltageregulation;• Steady-stateanddynamicstabilityenhancement;• Reducedfaultcurrent;• Reducedtransmissionlosses

SG2.0isaboutacompleteshiftfrombothpreviousgenerationofhardandsoftcomponentsofgridto itsmodernizeddigital version for enabling better integration of renewable energy resources.SG2.0facilitatestwo-waypowerandinformationflow,moreactiveconsumerparticipation,improvedqualityofserviceandresilienceofgridsinavariedandchallengingenvironment(Figure13).Itwillalsobemorepenetrating,andwillbeabletosensethesystemoverloadsandreroutethepowertopreventortominimizeapotentialoutage.Itwillacceptenergyfromvirtuallyanyfuelsourceandofferimprovedsecurityandresiliencyincaseofnaturaldisastersorthreats.Italsowillallowreal-timecommunicationbetweentheconsumerandutility,usheringinaneweraofconsumerchoice.

Furthermore,itwillleverageuponadvancementofpowerelectronicstomakethedistributionnetworkmoreefficientintermsofbothenergyandspaceoccupiedandexplorethepossibilitiesforhousingsomeofthecomponentsofthepowergridatremoteundergroundlocations.Themodernizationof soft components involves advanced digital information and telecommunication technologies.Business intelligence (BI) reporting solutionsof the smart gridwillmigrate to the real-timeandpredictiveanalytics.TheadvancedITofferingsincludeconsumerbehaviouranalytics,timeofuse-pricinganalytics,cloud-basedsolutionsandmostimportantlytheInternetofEnergy.TheInternetofEnergyintendstolinkthedistributedgeneration,energystorageandloadstobuildanenergygridwithinformationflowsandpowerflowssimultaneouslyandbi-directionally.SG2.0willfacilitateintegrationofrenewableenergysystems,thuspromotingmigrationtowardsafullydecarbonizedelectricitygeneration.

Advanced Power Electronics | Pg 17

Figure 13: Enablers of SG2.0

Smart use of carefully designed advanced power electronics equipment will form a controlledinterfacebetweenvarioussectionsofadistributionpowernetwork.SuchequipmentwillfunctionlikeconventionaltransformersbutwillhaveacapabilitytoseamlesslyrouteandcontroltheflowofbothACandDCenergysourcesand loads.Thisevolvingpowerelectronicequipment, solidstate transformers (SST), will enable energy efficient integration of distributed energy systems(sustainablepowersystemblockscomprisingof renewables,energystorageandDC/AC loads)withthemaindistributionnetwork.Thisdefinesthenextgenerationofpowersystemarchitecture,asdepictedinFigure14.

AnSSTisanAC-to-ACandAC-to-DCpowerconversionequipmentcombinedinoneunit. In itsmodernform,itwillusesemiconductorssuchasSiCforitsfabrication.Aconventionaltransformeroperatesatlinefrequencyof50Hz/60Hzandthereforeiscalledlinefrequencytransformer(LFT).Duetoitslowfrequencyofoperation,anLFTisverylargeinsizeandcanonlyhandleACpowertransfer. ForDC integration,many other conventional power electronic equipment are needed.Thisadverselyaffects thesystemefficiencyaccompaniedbya large (spatial) footprint.AnSSTon theotherhandcanbemuchsmallerandmoreefficient thanaconventionalLFTbasedAC/DCsystem.This isbecause,majorpowerconversion isexecutedatveryhigh frequenciesandadditionalequipmentisnotrequiredforDCsourcesorDCloads.SSTscanbeusedforregulatedpowerroutingfromdistributedsourcestoeitherACorDCloads.

Advanced Power Electronics | Pg 18

Figure 14: SST based advanced substations integrating a mixed (AC/DC) source-load eco-system

Asolid-state transformerusuallycontainsaveryhigh frequency transformer (Figure16), insidetheAC-to-ACconverterorDC-to-DCconverter,whichprovideselectricalisolationandcarriesfullpower.SSTscanactivelyregulatevoltageandcurrent.Theycanbedesignedtoconvertsingle-phasepowertothree-phasepowerandvice-versaandcaninputoroutputDCpowertoreducethenumberofconversions,forgreaterend-to-endefficiency.SSToffersseveralfunctionalitiesinsmartgridconfigurationsincluding,protectingloadsfrompowersystemdisturbances,protectingpowersystemfromloaddisturbances,integratingenergystoragesystems(energybuffers),providingDCportsforinterconnectionsofdistributedgenerationandsupportingvoltageandpowerprofiles.SSTcanplayanimportantroleinrealisingtheDC/ACzonalpowerdistributionsystemandcanbethelinkforthemicro-gridstothemediumvoltagetransmissionsystemaswellaslowvoltageACandlowvoltageDCsystemsasdescribedinFigure15.

Figure 15: Conventional smart grid 1.0 (communication devices external to the transformer)

Figure 16: Grid 2.0 using solid state transformer

Becauseoftheirdesign,SSTsdonothavelargecurrentlossesandthusgeneratelessheatthantheconventionaltransformerswithasimilarpowerload.SSTcanenablepowertransferfrommediumvoltage to lowvoltageorDC/AC loadsatasubstantially reducedweightandsize for thesamepowerrating.Withadvancedpowerelectroniccomponents(e.g.SiCMOSFETs),seamlessvoltageregulation,andactive&reactivepowercontrolispossiblewithouttheneedofadditionalauxiliarydevices. Voltage, frequency and other transients can be remotely controlled leading to amoreresilientdistributionpowernetwork.

Thearchitectureoftheconventionalgridincludingsmartgrid1.0isshowninsimplifiedmannerinFigure15.HeretheMVissteppeddowntoLVofabout415V,andthenisuseddirectlytoACloadsorisinterfacedwithmultipleconvertersdependingupontheendusetotheconcernedapplication.SimilararchitectureplatformusingsolidstatetransformerfordistributionisenvisagedasinFigure16.

Advanced Power Electronics | Pg 20

Table 1: Grid 2.0 benefits for Singapore

The Grid 2.0 architecture shows considerable advantages and flexibility in a relatively morecompactfootprint.Somekeyadvantagesareeliminationofconventional50Hztransformer,severalpowerconversionstagesandcomplexityofcontrol.VariousfunctionalbenefitsofGrid2.0baseddistributionnetworkforSingaporearesummarisedinTable1.

The advanced functionality is being developed and tested in theEnergyResearch Institute@NTU(ERI@N)inastate-of-the-arttestfacility,(Figure17.)SSTswillbedeployedinapplicationssuchasrenewableintegration,seamlessintegrationofPVinSingaporeandalsoaidinpossibleundergroundsubstationdevelopmentwhichwillfreeuppremiumlandspace.

Figure 17: ERI@N’s SST R&D lab at CleanTech One

Advanced Power Electronics | Pg 21

CONClUDiNG REmARKS Climatechangehasemergedasthepreeminentthreatthatcoulddestabiliseglobalsystemswiththeonsetofsealevelrise,extremeweatherevents,andextremetemperaturesaffectingeveryaspectofourcivilisation.Aglobalconsensusisgrowingtowardsacarbonfreeeconomyencompassingaholisticapproachofsustainablegrowthandsecurityofenergysupply.Cleanenergyandenergyefficiency form thekeyelementsof thisstrategy.Powerelectronics isseen tobe thedisruptivetechnologicalbreakthroughthatfacilitatesaparadigmshifttowardsanenergytransitiontocleanenergyaswellasamajorenablerforelectrificationandenergyefficiency.Powerelectronicsenableextremelyefficientconversionofelectricalpower,provideoptimalconditionsfortransmissionanddistribution,andenablesystem leveldigitalisation.Thus, theamountofelectricityprocessedbypowerelectroniccomponents,viz.SiCandGaN,willdoubleoverthenextdecade,reachingupto80%by2030.

Domainswherepowerelectronicsisenvisagedtomakemajorimpactinclude-Smart&SustainableBuildings, IndustrialEnergyEfficiency,Transportation,andSmartGrids. In thebuildingssector,power electronics can provide between 15% - 90% savings in areas including lighting, air-conditioning,escalators,plug loadmanagement,and integrationof renewables. In the industrialsector,upto60%energysavingsispossibleindrivesystemsforelectricmotorsaswellasdatacentres.Powerelectronicsisconsideredtobeindispensableinapplicationsrangingfromhybrid/electricvehicles,moreelectricaircrafts,andships.Theinternetofenergywithbi-directionalenergyflowbetweenallcomponentsandsystemswillbemadepossiblewithsolidstatetransformersthatrelyonadvancedpowerelectronics.

Theglobalmarketforpowerelectronicshasapproximatelygrownatacompoundannualgrowthrate(CAGR)of6.9%between2014and2019reaching~$16billionin2019.Asthedevicesavailablereachhigherpower ratings, viz. 1.7 kV in2015 to>12kVby2024, theapplicationdomains inelectricvehicles, renewables, industrial& railsystems,andeventually thepowergridwill reachtechnologicalmaturityandwillachieveeconomiesofscale.Withwidespreadadoption,costsofpowerelectronicswilldropover40%by2022andsystemlevelcostparitywillbeachievedoverthenext3-7years,thusacceleratingdeploymentsandadvancingtherenewableenergyandenergyefficiencydeploymentstrategies.AsasignatorytotheParisagreement,Singaporehascommittedtocurtailemissionintensityby36%from2005levelsby2030.Besidespowergeneration,emissionscontributionsof~17%emanatefromthebuildingsandtransportationsectorsand~60%emissionsareattributedtotheindustrysector.

As the 2050 emissions targets are being considered, the key strategies include deployment ofsolarphotovoltaicsonrooftopsalongwithfloatingsolaronreservoirs/oceanwaters,electrificationoftransport,energyefficiency,andlong-termdeploymentofhydrogenforgeneration&transport.Powerelectronicswillbeaverysignificantcontributorinthesedeployments.SignificantresearchanddevelopmenteffortsareongoingintheInstitutesofHigherLearninginSingapore,whichincludeexploringtheuseofadvancedpowerelectronicsinapplicationsrangingfromsolarPVoptimisers/inverters,AC/DCgrids,powersuppliesforelectricvehicles,buildingautomation,andsolidstatetransformersforSmartGrid2.0.Deploymentsofpowerelectronicswillpromoteenergyefficiency,power quality, grid resilience, andwill also optimise the useof real estate.Singapore’s energypolicy is based on three core dimensions: Energy Security, Energy Equity, and EnvironmentalSustainability. Itaimstoachieveonall these threedimensionsas theycannotbe thoughtof, inisolation.

Theglobalenergylandscapeischanging,andit’schangingfast.By2050,40%oftheend-useofenergywouldbeintheformofelectricity.Powerelectronicswill thusformthefoundationofthischange. Power electronics components, viz. SiC andGaN, aremaking rapid strides inmarketpenetrationandapplicationsrangingfromdrivesforindustrialequipmenttoapplicationsforsmartgridsarebeingactivelypursued.Astheworldinvestsinnewtechnologiesformitigationofclimatechange,powerelectronicswillusherinanewparadigmasacornerstoneforbothenergytransitionandenergyefficiency.

Advanced Power Electronics | Pg 22

REfERENCES

1. https://www.datacenterknowledge.com/archives/2016/06/27/heres-how-much-energy-all-us-data-centers-consume

2. https://www.iea.org/geco/renewables/

3. https://www.forbes.com/sites/energyinnovation/2018/12/03/plunging-prices-mean-building-new-renewable-energy-is-cheaper-than-running-existing-coal/#14233dc931f3

4. https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2018/Apr/IRENA_Report_GET_2018.pdf

5. https://www.bccresearch.com/market-research/energy-and-resources/power-electronics-technologies-markets-report.html

6. https://www.researchgate.net/figure/Typical-Building-Energy-Consumption-in-Tropical-Countries_fig1_28143794

7. https://www.poweramericainstitute.org/wp-content/uploads/2017/04/Power-Electronics-with-WBG-Materials.pdf

8. UnitedStatesdatacenterenergyusagereport,LawrenceBerkeleyNationalLaboratory,LBNL-100577

CleanTech One (CTO) 1 CleanTech Loop, #06-04Singapore 637141 specs@ntu.edu.sg | www.erian.ntu.edu.sg/specs