Energy Recovery Strategy Based on Ideal Braking Force Distribution for Regenerative Braking System of a Four-Wheel Drive Electric Vehicle

Under raising pressure of global energy and environmental issues in recent years, electric vehicles (EVs) have been an alternative solution of the automobile industry owing to its high energy efficiency, low noise, and zero emission. However, the short driving range is an urgent problem to be solved for EVs. Energy recovery is an important technology to improve energy efficiency and extend driving range of EVs. In this paper, an improved braking energy recovery strategy based on ideal braking force distribution (curve I) was proposed for the regenerative braking system (RBS) of a small four-wheel drive (FWD) EV. Compared with previous study, the improved braking energy recovery strategy gives more consideration to braking stability and covers broader braking situations of the vehicle. The braking energy recovery strategy is extensively validated through numerical simulations of a previously built vehicle system model under different fixed braking strength and continuously varying braking strength. The simulation results show that the proposed braking energy recovery strategy is able to effectively achieve the regenerative braking function under different braking conditions while ensuring braking efficiency and braking stability.