Page - 19 - in Emerging Technologies for Electric and Hybrid Vehicles

Energies 2017,10, 1217 Figure25. Structure for four-wheeldriveHEV[32]. Thisparticular systemusesavehicle controller whichemploysanumberofsensors toperceive thedrivingconditionandkeeps thevehiclestableby controlling thebrakecontrolandthemotorcontrolunits. 4. EnergySources EVscanget theenergy required to run fromdifferent sources. Thecriteria suchsourceshave to satisfyarementioned in [4], highenergydensityandhighpowerdensitybeing twoof themost important ones [30]. There areother characteristics that are sought after tomakeaperfect energy source, fast charging, longserviceandcycle life, lesscostandmaintenancebeingafewof them.High specificenergy is requiredfromasource toprovidea longdrivingrangewhereashighspecificpower helps to increase theacceleration. Becauseof thediversecharacteristics thatarerequiredfor theperfect source,quitea fewsourcesorenergystoragesystems(ESS)comeintodiscussion; theyarealsoused in differentcombinations toprovidedesiredpowerandenergyrequirements [4]. 4.1. Battery Batterieshavebeenthemajorenergysource forEVsfora longtime; thoughofcourse,was time hasgoneby,differentbattery technologieshavebeeninventedandadoptedandthisprocess isstill going on to attain thedesiredperformance goals. Table 5 shows thedesiredperformance for EV batteriessetbytheU.S.AdvancedBatteryConsortium(USABC). Table5.PerformancegoalofEVbatteriesassetbyUSABC.Data from[4]. Parameters Mid-Term Long-Term Primarygoals Energydensity (C/3dischargerate) (Wh/L) 135 300 Specificenergy(C/3dischargerate) (Wh/kg) 80 (Desired: 100) 200 Powerdensity (W/l) 250 600 Specificpower (80%DOD/30s) (W/kg) 150 (Desired: 200) 400 Lifetime(year) 5 10 Cycle life (80%DOD)(cycles) 600 1000 Price (USD/kWh) <150 <100 Operatingtemperature (◦C) −30 to65 −40 to84 Rechargingtime(hour) <6 3 to6 Fast rechargingtime(40%to80%SOC)(hour) 0.25 Secondary goals Self-discharge (%) <15(48h) <15(month) Efficiency(C/3discharge,6hcharge) (%) 75 80 Maintenance Nomaintenance Nomaintenance Resistance toabuse Tolerance Tolerance Thermal loss 3.2W/kWh 3.2W/kWh 19