Optimum energy management strategy of a hybrid electrical vehicle based on efficient power distribution and battery discharge capacity

Abstract

Efficient power distribution between prime movers, the internal combustion engine, and the electric motor of a hybrid electric vehicle (HEV) plays a significant role in its energy management strategy to reduce the overall fuel consumption and CO2 emissions. This study uses AVL Cruise Software to analyze the overall fuel consumption of a light-duty commercial vehicle (LCV) in two different hybrid configurations, known as P2 and P4, in the literature. The simulated results show that the fuel consumption can be improved by 17.7% using the P2 configuration. In contrast, the P4 design accounts for only a 15.6% improvement in a sustainable charge WLTC test compared to the base vehicle having a conventional powertrain. To find an optimum power distribution between the internal combustion engine and the electric motor, research is focused on only the P2 configuration. The results revealed that, for a specific velocity range, a particular internal combustion engine and electric motor power ratio and maximum permissible battery power discharge capacity are required to improve fuel economy. It is shown that an additional 5.1% improvement in the vehicle's overall fuel consumption can be achieved in a sustainable charge WLTC test. Finally, this research concentrates on incorporating the online traffic data via V2V, V2I, and GPS communication into energy management strategy to predict the future vehicle velocity profile and instruct the driver on an eco-driving procedure. The fluctuating speed at the prediction horizon is smoothened using Savitzky–Golay filter, requiring the driver to maintain a constant speed driving as much as possible. The result showed a potential 6.1% improvement in fuel efficiency when an optimum P2 configuration is used.