Research on the Efficiency Optimization Control of the Regenerative Braking System of Hybrid Electrical Vehicle Based on Electrical Variable Transmission

Electrical variable transmission (EVT) is a novel electromechanical energy converter that can be applied in hybrid electrical vehicle (HEV). In this paper, the hybrid electrical vehicle based on EVT (EVT-HEV) and the efficiency optimization strategy of regenerative braking system (RBS) is studied. Firstly, this paper analyzes the dynamic coupling mode of EVT-HEV and establishes the expression of the dynamic coupling relationship between EVT and the engine. Then, four different braking modes including two novel ones are divided. Next, a hierarchical controller is proposed in which the rule-based control strategy is used for braking mode switching and neural network algorithm is used for the optimal efficiency control for the system. The simulation of the control strategy is carried out under New European Driving Cycle (NEDC) based on the joint platform of CRUISE and MATLAB software. And the results indicate that the proposed strategy can improve the performance of RBS in EVT-HEV. Thus the research in this paper can bring a new theoretical foundation for the application of EVT in HEV and is of great significance to enrich the energy management strategies of EVT-HEV.