Evaluation of a mild-hybrid electric combat vehicle with energy management

Abstract

The desire to reduce fuel consumption and gas emissions, along with increasing demands on electrical energy is driving the evolution of vehicle power system architectures well beyond the conventional single alternator and battery. Amongst the different power system architectures available, are mild-hybrid electric architectures. Such architectures may offer flexibility in balancing the trade-offs associated with minimising fuel consumption, and greater capacity to meet electric energy demands. They allow for a wide range of energy management strategies to be investigated. Such strategies are able to accommodate for the need to reduce fuel consumption, undesirable gas emissions, and the need to meet the increased dependence on electrical energy. The strategies can be implemented by vehicle power management systems running energy management algorithms. Such systems are becoming more common in commercial vehicles, however, they are not commonly found in current military vehicles. This thesis focusses on evaluating the impacts caused to vehicle acceleration, fuel consumption, the time to fully charge/discharge the vehicle battery pack, and the electrical conversion efficiency, when introducing energy management strategies into a baseline mild-hybrid electric combat vehicle under different military stationary and moving scenarios. The scenarios were selected because current vehicle manufacturers and academia have primarily focussed on investigating energy management strategies in urban environments. In comparison, a study involving military scenarios allows a new application domain to be investigated. The thesis describes the mild-hybrid electric combat vehicle baseline, and presents the results of comparing the baseline against one that has been extended to include additional energy management strategies under different military scenarios.