Page - 268 - in Emerging Technologies for Electric and Hybrid Vehicles

Energies 2017,10, 437 (a) (b) Figure3.Leveranalysis for the inputsplit typeby a/i. (a) a/i is larger than2; (b) a/i is smaller than2. D L 350* 5 /) % 'PIKPG 4 /) 5 /) % 'PIKPG 4 /) Figure 4. Speed, torque, and power ratio versus a/i when ωe = 1500 rpm, Te = 100 Nm, ωout=2000rpm. InFigure5,aschematicdiagramof the inputsplit typePSTusingthesinglePGisshown,which is selected fromthedesignprocedure. ThePST inFigure5consistsofoneengineat thecarrier (C), MG2at theringgear (R),andMG1at thesungear (S).ThePSTinFigure5aprovides twooperating modeswhendriving; (1)electricvehicle (EV)and(2)powersplitmode. In theEVmode, thevehicle ispropelledbyMG2usingelectricenergy(Figure5b). In thepowersplitmode, theenginepower is split at thePGandtransmittedtoMG1andto theoutput (Figure5c).At thismoment, thepowermay circulate throughtheclosedpath,dependingonthevehiclespeed. UsingthePSTinFigure5asareference topology,adesignmethodologyof thePHEVthatcan realizemoreoperatingmodeswithhighefficiency is investigated. Torealizemore thantwooperatingmodes, thedegreeof freedomof thesinglePGneeds tobe changedusingtheclutchandbrake. InFigure6a, thepossiblepositionswheretheclutchandbrakecan beaddedareshown. Since thePGhas threenodes (sun, carrier, andringgear), theclutches,CL1,CL2, CL3,andthebrakes,BK1,BK2,andBK3, canbeaddedateachnode, as showninFigure6a [11,15]. Mathematically, thenumberofcombinations that canbeconstructed fromthreeclutchesandthree brakes is 26. However, infeasible combinations canbe eliminatedby considering the real driving environment. In thepowersplitmode, inotherwords, in thehybridelectricvehicle (HEV)modein 268