Seite - 154 - in Emerging Technologies for Electric and Hybrid Vehicles

Energies 2017,10, 1503 Figure15.External short-circuit faultdetectionandself-recoverycurve. The over-charged and over-discharged states are another two faults that can cause permanent damagetotheinternalstructureofbatteries. Intheprototypesystem,over-chargedandover-discharged fault-diagnosis schemes are both integrated. Theprotection and self-recoveryprocesses canbe seen in Figures 16 and 17, respectively. As observed in Figure 16, after the batterieswere fully charged, theover-chargedfaultwasreported,andthechargingswitchwasturnedoffbythecontrollertoisolatethe chargingmodulefromthecells. Totriggerthechargingfunction,thechargerneedstoberemovedtoallow thechargingmoduletorecoverautomatically. Similarly, theover-dischargedfaultwasdetectedwhenany cellof thebatterypackreachedthecut-offvoltage,asshowninFigure17. Thedischargingswitchwas turnedofftoisolatethebatteryfromtheoutputmoduleorload.Usingtheself-lockingandself-recovery function, theover-chargedandover-dischargedfaultscanbemanagedeffectivelytopreventdamageto thebatteriesandpossible injury to theuser. Similarly,over-current,over-temperatureandbroken-wire faultdiagnosesof thebattery systemwere implementedusing theproposedschemes in theactual battery-powersystem. Figure16.Over-chargedfaultdetectionandself-recoverycurve. 154