ResearchonthesystemconfigurationandenergycontrolstrategyforparallelhydraulichybridloaderSunHui,,JingJunqingJiangsuXuzhouConstructionMachineryResearchInstitute,Jiangsu,ChinaAccepted30October2009.Availableonline22November2009.http://dx.doi.org/10.1016/j.autcon.2009.10.006,HowtoCiteorLinkUsingDOIPermissions&ReprintsAbstractAimedatthefrequentstarts/stopsoperationcharacteristicsoftheloader,anenergysavingschemewithparallelhydraulichybridsystemisproposedtoregenerateandreusethebrakingenergynormallylostinaconventionalloader.Hydraulichybridsystemisdesignedandsizedtocapturebrakingenergyfromnormal–moderatebrakingoperatingmodeswhileensureshybridsystemworkinginhigherefficiencyregion.Accordingtothehigherpowerdensitycharacteristicofhydraulichybridsystem,theregenerativebrakingstrategyandenergyreusestrategyaredesignedtocoordinateallthepowertraincomponentsinanoptimalmannerwhilesatisfyingperformanceconstraintsofloader.Energycontrollerusinglogicthresholdapproachisbuiltuptocontrolthedynamictransitionsamongthevariousoperationmodes.Simulationandexperimentalresultsshowtheparallelhydraulichybridloader(PHHL)effectivelyrecoveredandreusedthebrakingenergy,improvedtheworkingperformanceofloaderandeffectivelyreducedthefuelconsumption.KeywordsLoader;Hydraulichybridsystem;Brakingenergyregeneration;Energymanagement;Hydraulicpump/motor1.IntroductionWiththerisingconcerninaglobalscaleenvironmentalissue,energysavinginautomobilesisaveryimportantsubject[1]and[2].Off-roadvehicleshavebeenpaidmuchattentioninthefieldofenergysavingandenvironmentprotection,forthereasonoftheirlargeapplicationquantities,highfuelconsumptionandbademissions[3].Loaderhasthecharacteristicsoffrequentstarts/stopsandlargervehicleweightwhichgeneratedsignificantamountsofbrakingenergy.Usually,thispartofenergyiswastedbythefrictionalbrakingsystemwhichcausedtheenergylossandheatgenerationinthesystem.Therefore,thebrakingenergyrecoveryandreuseisapromisingwaytoimprovefueleconomyandworkingperformanceofoff-roadvehicles[4]and[5].Thereisawealthofliteraturefocusedonhybridelectricengineeringvehicles,butthepublicationsdevotedtohydraulicpropulsionoptionsarerelativelyscarce[6]and[7].Aparallelhydraulichybridloaderisonethatcontainstwosourcesofpower,withonesourcebeinganinternalcombustionengine.Theotherpowersourceishydraulicpump/motorandaccumulators.OnefeatureofPHHListheabilitytorecoverenergynormallylostduringbrakingandstoretheenergyinahydraulicaccumulator.Thestoredenergyisusedtoprovidethetotalcommandpowerduringloaderlaunchingorprovideauxiliarytractionpowerduringshovelingoperationmode,whichavoidstheengineworkingintheregionsoflowefficiencyandsignificantemissions.Inthispaper,anenergysavingschemewithparallelhydraulichybridsystemisproposedtocapturethebrakingenergynormallylosttofrictionbrakes.Hydraulichybridsystemisdesignedandsizedtocapturebrakingenergyfromnormal-moderatebrakingoperatingmodeswhileensureshybridsystemworkinginhigherefficiencyregion.Accordingtotheadvantageofhighpowerdensityforhydraulicaccumulatorandtheoperationcharacteristicsofloader(stop-and-godutycycles),theregenerativebrakingstrategyandenergyreusestrategyaredesignedtocoordinateallthepowertraincomponentsinanoptimalmannerwhilesatisfyingperformanceconstraints.Energycontrolstrategyisbuiltuparoundtheconceptofmulti-levelhierarchiccontrolsystem.PHHLsimulationmodelandthecontrolsystemsimulationmodelbasedonthepro...
