Research on regenerative brake technology of electric vehicle based on direct-drive electric-hydraulic brake system

A novel brake-by-wire system based on a direct-drive electro-hydraulic unit, which is able to control braking force flexibly, was designed to improve braking performance and recovery efficiency in electric vehicles. The structure of the brake unit is discussed in detail as well as the composition of the brake system. Since this novel system is required to coordinate with the regenerative system because of flexibly controlled friction force, the regenerative strategy is discussed in detail. An experiment is completed to prove that this novel unit is technologically feasible, and an electric vehicle co-simulation model based on MATLAB/Simulink and AMESim is established to prove that the unit and recovery strategy are able to recover braking energy as much as possible in the premise of braking safety. The simulation result shows that this novel system is able to control friction force flexibly according to motor status, so the regenerative efficiency is significantly improved especially in light braking.