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 the 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 addition 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 with the temperature of the battery pack and with the energy management strategy (EMS). The proposed work aims to analyse the performance of a Plug-In series hybrid vehicle (Plug-In HEV) depending on the temperature of battery pack and the EMS. The considered Plug-In HEV is equipped with a hydrogen-fuelled internal combustion engine that is used as REx. First, a lumped dynamic thermal model of is proposed to compute the performance of the battery pack depending on the operating temperature. Moreover, a Rule Based (RB) and a Pontryagin’s Minimum Principle (PMP) Energy Management Strategy (EMS) are considered. The results in terms of fuel consumption are discussed accounting for the battery lumped thermal dynamics. The effects of the battery pack thermal transients according to the EMS decisions are analysed. The relationship between the EMS metrics, the battery pack downsizing and the cooling mechanism of the battery pack is discussed. The authors will observe how the adoption of an optimal EMS can help to simplify the vehicle powertrain by allowing a battery pack downsizing and avoiding the use of an active cooling system of the battery pack.