Load sharing control of dual energy storage power system in heavy duty series hybrid vehicles

Heavy duty off-road vehicle (HDOR) duty cycles are very different than passenger car cycles. HDOR duty cycles are characterized by heavy transient loads and highly varying constant power demands. Straddle carriers and mine loaders can operate 20 hours per day while cars are most of the time idle. Batteries and supercapacitors have different qualities in terms of power and energy density and cyclic life time. Hybridization of HDOR driveline reduces fuel consumption and contributes to cleaner workspace environment due to reduced emission. This paper presents new load sharing control method for battery & supercapacitor series hybrid heavy-duty off-road vehicle. Both energy storages have separate DC/DCconverters. Control strategy ensures that both energy storages are used optimally based on their characteristic strengths. Implications of this control strategy are reduced consumption and more importantly improved battery lifetime. Control strategy is presented; simulation results for control performance are presented and discussed.