Page - 10 - in Emerging Technologies for Electric and Hybrid Vehicles

Energies 2017,10, 1217 managementsystem.Thepropulsionsubsystemhastheelectricmotor,powerconverter, controller, transmission and thedrivingwheels as its components. The auxiliary subsystem is comprisedof auxiliarypowersupply, temperaturecontrol systemandthepowersteeringunit. Thesesubsystems areshowninFigure10. Figure10.EVsubsystems.Adaptedfrom[4]. Thearrows indicate theflowof theentities inquestion.Abackwardflowofpowercanbecreated byregenerativeactions likeregenerativebraking. Theenergysourcehas tobereceptive tostore the energysentbackbyregenerativeactions.Mostof theEVbatteriesalongwithcapacitors/flywheels (CFs)arecompatiblewithsuchenergyregenerationtechniques [4]. 3.1.GeneralEVSetup EVscanhavedifferentconfigurationsasshownin[4]. Figure11ashowsafront-enginefront-wheel drivevehiclewith just the ICEreplacedbyanelectricmotor. Ithasagearboxandclutchthatallows hightorqueat lowspeedsandlowtorqueathighspeeds. There isadifferentialaswell thatallowsthe wheels torotateatdifferentspeeds. Figure11bshowsaconfigurationwith theclutchomitted. Ithas afixedgear inplaceof thegearboxwhich removes the chanceofgetting thedesired torque-speed characteristics. TheconfigurationofFigure11chas themotor,gearanddifferential asasingleunit thatdrivesboththewheels. TheNissanLeaf,aswellas theChevroletSpark,usesanelectricmotor mountedat the front todrive the frontaxle. InFigure11d,e, configurations toobtaindifferentialaction byusing twomotors for the twowheelsareshown.Mechanical interactioncanbe further reduced byplacingthemotors inside thewheels toproducean ‘in-wheeldrive’.Aplanetarygearsystemis employedherebecauseadvantages likehighspeedreductionratioandinlinearrangementof input andoutput shafts.Mechanicalgear systemis totally removed in the last configuration (Figure11f) bymountinga low-speedmotorwithanouter rotorconfigurationonthewheel rim.Controllingthe motorspeedthuscontrols thewheel speedandthevehiclespeed. EVscanbebuiltwith rearwheeldrive configurationaswell. The singlemotorversionof the TeslaModelSuses thisconfiguration(Figure12). TheNissanBladeGlider isarearwheeldriveEV with in-wheelmotorarrangement. Theuseof in-wheelmotorsenables it toapplydifferentamountof torquesateachof the tworearwheels toallowbettercornering. 10