The Analysis of Energy Recovered during the Braking of an Electric Vehicle in Different Driving Conditions

Abstract

The partial recovery of kinetic energy during braking allows the vehicle’s battery to be additionally charged and thus extends the range of an electric vehicle. Because of the different operating strategies of the braking energy recovery system, it is important to understand the factors influencing the level of recovered energy. The driving conditions at the place of use have a direct impact on the energy efficiency of an electric vehicle. The purpose of this paper was to analyze the energy recovered during braking in different driving conditions. The tests were based on the parameters of actual trips made along urban and suburban routes, and express roads. The collected actual speed profiles were used for the simulation studies. AVL cruise vehicle simulation software was used in the study. Simulation tests revealed that the levels of energy recovered during braking in an electric vehicle were the highest in urban conditions. The amount of energy recovered during urban driving can account for 20% of the total trip energy. In driving conditions characterized by different intensities caused by trips at different times of the day, similar values of recovered energy were recorded. When driving in the afternoon hours, the level of recovered energy per 1 km was about 2% lower than when driving in rush hour conditions. From the results presented in this paper, it can be concluded that driving conditions have an impact on the level of recovered energy. The type of road on which the electric vehicle drives is particularly important.