Seite - 152 - in Emerging Technologies for Electric and Hybrid Vehicles

Energies 2017,10, 1503 ThefrontpanelinFigure10containsinformationsuchasthecurrentconfigurationofthebatterypack andtherespectiveminimum,maximumandmeanvoltagesandSOCvalueof thebatterypack.Theother functionalmodules thatcontainthecells’ informationareshowninFigure10. Intheconfigurationpage, asshowninFigure11, fouroptionsof thebattery-cell typescanbeselected. Theuserscanchoose the materialof thephysical cells connected to thecontrolboard, thebattery-cell capacityandbattery-cell maximumdischargingcurrent. The lastparameter is thegrouping topologyof thebatterypack that dependsonthephysicalbattery-cell layout, that is, seriesorparallel. Thesystemcanbe initializedto proceedwith theproper functionand faultdiagnosis operation. However, if the series-cell layout is definedbytheactualparallel-cellconfiguration, thesystemwillnot functionforsafetypurposes. Thedata-acquisitionmoduleof thepowersystemisessential for theSOCestimationandfault diagnosis. Itwillaffecttheoverallperformanceofthesystem. Inthispaper,anaccuratedata-acquisition module for the battery cell is implementedwith a total measurement error of less than 1.2mV. Theprecisedataensure that theaccuracyof theSOCestimationandthesafetyof thesystemcanbe monitored. Thecell-monitoringpageof theGUIcanbeseen inFigure12. Forexample, thesystemcan estimate theSOCofeachcell. TheSOCvaluesarequiteclose to thevaluesobtainedbytheextended Kalmanfilter (EKF).TheproposedSOCestimationexhibits a closematchwith theEKFunder the regularpulsedischarge test (PDT),as seen inFigure13.Here, the2Resistor-Capacitor (RC)equivalent circuitmodel (ECM) is applied for theEKF-basedSOCestimation. The functionof the SOCwith respect toUOC isdescribedas follows[33]: UOC=3.397−0.19SOC+0.087logSOC−0.054log(1−SOC), (6) whereSOC∈ (0, 1). Figure12.Cell-monitoringpanelofGUIforproposedbattery-powersystem. Figure13.ComparisonofExtendedKalmanfilter (EKF)withproposedSOCestimationunderregular pulsedischarge test. 152