Effects of the battery pack temperature on the energy management strategy and fuel consumption of a series hybrid quadricycle

Nowadays, a push towards decarbonisation to reduce the problem of environmental pollution is increasingly pressing. In the current automotive context, a tendency among the cars manufacturer to consider the development of hybrid vehicles is growing. Indeed, thanks to the battery downsizing due to the presence of the range extender (REx), a hybrid electric vehicle (HEV) allows to overcome the limitations of pure electric vehicles (EV) such as the infrastructure which is linked to the battery charging process. Moreover, the performance of battery in terms of efficiency and operating limits are strictly related to the temperature of battery pack and to the energy management strategy (EMS). The proposed work aims to analyse the performance of a series hybrid vehicle (S-HEV) depending on the temperature of battery pack and the EMS. The considered S-HEV is equipped with a hydrogen-fuelled internal combustion engine that is used as REx. First, a lumped thermal model of the battery pack is proposed to compute the performance of the pack depending on the operating temperature. An optimal EMS is considered which is bases on the Pontryagin’s minimum principle. The relationship between the battery temperature, the EMS metrics and the performance of the powertrain in terms of fuel consumption are discussed, the results are shown. Moreover, a lumped dynamic thermal model of the battery pack is proposed to account for the battery performance due to the thermal transients. The results in terms of fuel consumption are discussed accounting for the battery lumped thermal dynamics and compared with the fixed temperature analyses that are performed before to investigate on the effects of the battery pack thermal transients according to the EMS decisions.