Uncoupled Braking Energy Recovery System Based on Pneumatic ABS Solenoid Valve

To reduce the energy consumption of electric bus, the working principle, configuration and control strategy of uncoupled braking energy recovery system (URBS) based on the pneumatic ABS solenoid valve were proposed. The pneumatic dynamic characteristics of the ABS valve were tested and the segmented ABS solenoid valve pressure regulating model was proposed based on the characteristics. To verify the feasibility of URBS, a joint simulation platform was built based on Matlab/Simulink/Stateflow and AVL Cruise. The vehicle control and pneumatic braking characteristic module were built based on Matlab/Simulink/Stateflow. Other modules were built based on AVL Cruise. They were integrated through API interface. Taking a 12 m electric bus as an example, the performance of URBS was compared and verified. According to the simulation results, the braking torque has a certain overshoot, but the vehicle deceleration changes smoothly, and the vehicle speed can accurately track the target value. It shows that the pneumatic ABS solenoid valve can meet the requirements of URBS for braking force regulation. The vehicle energy consumption under different loads was compared, when the simulation condition is the comprehensive conditions of typical cities in China. The 100 km power consumption of vehicle was taken as evaluation index. Compared with the non-braking energy recovery scheme, the power consumption can be reduced by 32.94% when the load is no load. The power consumption can be reduced by 30.47% when the load is half load. The power consumption can be reduced by 28.12% when the load is full load. Compared with the coupled braking energy recovery scheme, the power consumption can be reduced by 13.47% when the load is no load. The power consumption can be reduced by 12.10% when the load is half load. The power consumption can be reduced by 11.32% when the load is full load. Results show that the energy saving effect is remarkable. The relevant research can provide reference for the production of URBS for commercial vehicles in China and provide solution for improving the economy of new energy commercial vehicles.