Electric and Hybrid Vehicles With Two Prime Movers

The importance of reducing emissions and energy consumption of the vehicles for individual mobility is continuously growing, particularly considering the increasingly chaotic urban context. Therefore the importance of reducing fuel consumption in automotive field is and will be a key factor of the development of the future vehicles. To achieve this target, full-electric and hybrid-electric vehicles start to be adopted and probably will be strongly developed in the next future. Furthermore, thanks to the presence of an electric motor, a regenerative braking strategy can be adopted in order to recharge the battery, recovering part of the kinetic energy of the vehicle, rather than dissipating it with the traditional passive brakes. The amount of energy that can be regenerated can be significant in case of urban driving, with frequent start and stop maneuvers and low average speed. In this thesis, new high fidelity simulation models of both full-electric and hybrid-electric vehicles were built and a development and optimization procedure of the powertrains driving strategies is presented. The models take into account all the limitations to the maximum performance of each component of the powertrain in order to individuate the most critical components and to drive their optimal sizing. In addition, a reliable evaluation of the efficiencies, dissipation, temperatures and energy flows through the different components of the powertrain is performed to evaluate the whole powertrain efficiency and performance. Finally, different torque-split control strategies are defined, compared and optimized in order to maximize the vehicle efficiency and performance, considering both full-electric and hybrid-electric vehicle