Page - 301 - in Emerging Technologies for Electric and Hybrid Vehicles

Energies 2016,9, 997 Figure19.Optimizationmodel for theHEVenergymanagementkeyparameters. Table11.KeyparametersofDIRECTalgorithm. KeyParameters Value Maximumnumberof iterations 20 Maximumnumberof functioncalculation 1000 Maximumdivisiontimepersideofhyper-rectangle 100 Global/localweightingcoefficient 0.0001 Relativeerror 0.01% x1, x2, x3, x4, x5, x6, x7 are the parameters that need to be optimized. Themeaning of these parametersaredescribed inTable3. The initialvalue, range,andoptimizedvalueof theseparameters areshowninTable12. Table12.OptimizedresultofkeyparametersbasedonDIRECTalgorithm. Parameters InitialValue LowerLimit UpperLimit OptimizedValue x1 0.4 0.2 0.6 0.3889 x2 0.3 0.1 0.5 0.3556 x3 70 50 70 53.333 x4 40 30 50 47.963 x5 20 15 25 22.222 x6 50 40 60 50.667 x7 15 10 20 18.333 Changes to the parameters to be optimized have a big impact on the fuel economy. In the optimizationprocessofDIRECTalgorithm, theequivalent fuel consumptionper100kmfordifferent iterationfunctionevaluations is showninFigures20and21, respectively. 301