te(uptothesafelimit)necessarytosatisfythehighpowerrequirements.Twoconfigurationsofhybridpowersourcesweretestedinthisstudy.Bothconfigurationsusedthesamefuelcell,powerconverterandcontrolalgorithm;theonlydifferencebetweenthemwasthebatteryarraysize.Thestudyresultsshowthatsuchfuelcell/batteryhybridpowersourcesachievedmuchgreaterspecificpowerthanthefuelcellalone.Thefirsthybridpowersourcestudied,whichusedasix-cellbattery,demonstratedaWpeakpowercapability,whichisthreetimesthatofthefuelcellalone.Thesecondhybridpowersourcestudied,whichusedaneight-cellbattery,achievedahigherpeakpowerofW.Besidestheadvantageofprovidinghigherspecificpower,theactivehybridsofferedadvantagesofabroaderrangeandbetterregulationoftheoutputvoltage,asmallerfuelcellstress,asmallerweightandvolume(forafixedpeakpowercapability)ofthesystem,andfasterresponseatstartupandduringstepchangesofpowerdemand.Inthefollowingsection,thesyst耗。