Page - 269 - in Emerging Technologies for Electric and Hybrid Vehicles

Energies 2017,10, 437 which theengineandMG2worktogether, theengineandMG1shouldalwaysoperate togetherdueto the followingreasons: (1) Theengineneeds tosupply thepower topropel thevehicleandtogenerateMG1. (2) Whentheengineworks,MG1is requiredtocontrol theengineoperationontheOOL. Fromtheaboveconstraints, it isseenthatclutchesCL2andCL3shouldalwaysbeengaged,which meansthatCL2andCL3arenotnecessary,asshownFigure6b. Therefore, thenumberofcombinations becomes24(=16)byeliminatingCL2andCL3. (a) (b) (c) S C R PG /) '0) /) Output $CVVGT[ Electrical path S C R PG /) Output $CVVGT[ Electrical path '0) /) S C R PG /) Output $CVVGT[ Electrical path '0) /) Figure5.Referencepowersplit transmission. (a) Inputsplitpowersplit transmission(PST); (b) electric vehicle (EV)mode; (c)Powersplitmode. (a) (b) /) '0) /) Output $CVVGT[ Electrical path S C R PG $- $- $- %. %. %. /) '0) /) Output $CVVGT[ Electrical path S C R PG $- $- $- %. Figure6. Schematicdiagramfor thereference topology. (a)Allpossible locations foraddingtheclutch andbrake[11]; (b)Feasible locations foraddingtheclutchandbrake. ByaddingCL1,BK1,BK2,andBK3tothereferencetopology, thefollowingmodescanberealized: EV#1: Thevehicle ispropelledonlybyMG2.MG1andtheengineareoff.Noclutchorbrake is required. Powersplit: Thismodecanbe implementedasexplainedinFigure5c.Noadditionalclutchor brake isneededfromthereference topology. EV#2: MG2andMG1propel thevehicle together. Since theenginedoesnotwork, thereactionforceactingonthecarriermustexist to transmit theMG1torquethrough thePG.Therefore, thecarrier isfixedbyactivatingBK2. Parallel: TheengineandMG2propel thevehicleusingtheparallelpath.MG1doesnot function, whichrequiresBK3tomaketheMG1speedzero. Theenginepower is transmittedto theoutput throughthemechanicalpathwithoutusingtheelectricalpath.MG2works usingthebatteryenergy. Series: To implement thismode, theengineneeds tobeseparatedfromtheoutput,which requiresCL1todisengage thepower fromtheengineandBK1togroundtheringgear. TheengineonlydrivesMG1togenerate theelectricalpower,which is transmittedto theoutput throughtheelectricalpath. 269