The Control Strategy And Simulation For CVT Hybrid Vehicle When Regenerative Braking

Regenerative braking (energy recovery braking) is one of key advantages of HEV, which has a direct impact on fuel economy, emission and vehicle security. When HEV is braking, regenerative braking system will make the motor become a generator for generating electricity through the power train system and supplying the whole braking forces or partial braking forces at the same time. Finally, electric energy is saved into the battery pack. Regenerative braking not only realizes the braking and deceleration, but also recovers the kinetic energy. The research show, that regenerative braking raises fuel economy up to 20% for HEV, and increase driving distance up to 20% for EV.Focus on Mild Hybrid Electric Vehicle with ISG The deeply theoretical researching, system simulation and experiment are completed in this paper. The main results include:1. Base on the analysis of tradition vehicle braking dynamics, considering the need of HEV, proposed regenerative braking force distribution strategy according to battery SOC and vehicle severity.2. Base on the analysis of motor numerical model, proposed an optimal operation line for motor which can enable it working in the high efficiency generating area. Then proposed a CVT ratio and clamping force control strategy to enable motor working in the optimal operation line.3. Considering the parts and parameters of HEV, built vehicle dynamics simulation model which mainly adapted a backward simulation assisting by forward simulation idea under Matlab/Simulink.4. Compared the simulation result between using CVT and MT in test vehicle which used the same ratio area. The simulation results in different drive cycles show that using the proposed CVT ratio control strategy can effectively improve battery SOC, energy absorbing rate and motor generating efficiency. And motor can work in the optimal operation line ideally.5. Considering the need of HEV with ISG, built a test bench, control desktop under dSPACE and rebuilt CVT and ISG motor model.6. Test according to different velocity and severity in the test bench .Result show that using the proposed regenerative braking control strategy and CVT control strategy...