Page - 36 - in Emerging Technologies for Electric and Hybrid Vehicles

Energies 2017,10, 1217 capability todoitautomatically [46].AllDCchargingsystemshasapermanentlyconnectedElectric VehicleServiceEquipment (EVSE) that incorporates thecharger. Theirclassification isdonedepending onthepower levels theysupply to thebattery: • Level1: Theratedvoltage is450Vwith80Aofcurrent. Thesystemiscapableofprovidingpower upto36kW. • Level 2: It has the samevoltage ratingas the level 1 system; the current rating is increased to 200Aandthepower to90kW. • Level3:Voltage in thissystemisratedto600V.Maximumcurrent is400Awithapowerrating of 240kW.Table 20 shows theDCcharging characteristics definedbySociety ofAutomotive Engineers (SAE). Table20.SAE(SocietyofAutomotiveEngineers)DCchargingcharacteristics.Data from[46]. DCChargingSystem DCVoltageRange(V) MaximumCurrent (A) Power (kW) Level1 200–450 ≤80 ≤36 Level2 200–450 ≤200 ≤90 Level3 200–600 ≤400 ≤240 6.3.WirelessCharging Wireless chargingorwirelesspower transfer (WPT) enjoys significant interest becauseof the conveniences itoffers. Thissystemdoesnotrequire theplugsandcablesrequired inwiredcharging systems, there isnoneedofattaching thecable to thecar, lowriskof sparksandshocks indirtyorwet environmentandlesschanceofvandalism. Forerunners inWPTresearch includeR&Dcentersand governmentorganizations likePhillipsResearchEurope,EnergyDynamicLaboratory (EDL),USDOT, DOE;universities includingtheUniversityofTennessee, theUniversityofBritishColumbia,Korea Advance InstituteofScienceandTechnology(KAIST);automobilemanufacturers includingDaimler, Toyota, BMW,GMandChrysler. The suppliers of such technology includeWitricity, LG,Evatran, HaloIPT(ownedbyQualcomm),MomentumDynamicsandConductix-Wampfler [27].However, this technology isnotcurrentlyavailable forcommercialEVsbecauseof thehealthandsafetyconcerns associatedwith thecurrent technology. Thespecificationsaredeterminedbydifferent standardization organizationsindifferentcountries:CanadianSafetyCode6inCanada[83], IEEEC95.1intheUSA[84], ICNIRPinEurope[85]andARPANSAinAustralia [86]. Therearedifferent technologies thatarebeing considered toprovideWPTfacilities. Theydiffer in theoperating frequency, efficiency, associated electromagnetic interference (EMI),andother factors. Inductivepower transfer (IPT) is amature technology, but it is only contactless, notwireless. Capacitivepower transfer (CPT)hassignificantadvantageat lowerpower levelsbecauseof lowcost andsize,butnot suitable forhigherpowerapplications likeEVcharging. Permanentmagnetcoupling power transfer (PMPT) is lowinefficiency,other factorsarenot favorableaswell. Resonant inductive power transfer (RIPT) aswell asOn-line inductivepower transfer (OLPT) appears tobe themost promisingones,buttheir infrastructuretmaynotallowthemtobeaviablesolution.Resonantantennae power transfer (RAPT) ismadeonasimilarconceptasRIPT,but theresonant frequency in thiscase is inMHzrange,which is capableofdamage tohumans ifnot shieldedproperly. The shielding is likely tohinder rangeandperformance;generationof suchhigh frequencies isalsoachallenge for powerelectronics [87]. Table21comparesdifferentwirelesschargingsystems in termsofperformance, cost, size, complexity, andpower level. Wireless charging for personal vehicles is unlikely to be availablesoonbecauseofhealth,fireandsafetyhazards,misalignmentproblemsandrange.Roads withWPTsystemsembeddedinto themforchargingpassingvehiclesalso facemajorcost issues [27]. Onlyafewwirelesssystemsareavailablenow,andthose tooare in trial stage.WiTricity isworking withDelphiElectronics,Toyota,HondaandMitsubishiMotors. Evatran iscollaboratingwithNissan 36