Hydraulic Regenerative Braking System

Hydraulic regenerative braking system is an important branch of hybrid technology, which has the advantage of high power density and the ability to accept the high rates/high frequencies of charging and discharging, therefore hydraulic regenerative braking technology is well suited for off-road vehicles and heavy-duty trucks. Relatively lower energy density and complicated coordinating operation between two power sources require a special energy control strategy to maximize the fuel saving potential. This paper presents a new configuration of parallel hydraulic regenerative vehicle (PHRBV) to improve the braking energy regenerated potential and engine work efficiency. Based on the analysis of optimal energy distribution for the proposed PHRBV over a representative urban driving cycle, a fuzzy torque control strategy based on the vehicle load changes is developed to real-time control the energy distribution for the proposed PHRBV. Simulation results demonstrate that the proposed PHRBV with torque control strategy takes advantage of the high power density and efficiency characteristics of the hydraulic regenerative braking system minimizes the disadvantages of low energy density and effectively improves the fuel economy of PHRBV.