Research on Transmission Efficiency Oriented Predictive Control of Power Split Hybrid Electric Vehicle

Power split hybrid electric vehicle (HEV), which enables free adjustment of the engine, shows excellent performance in energy saving. The fuel economy of HEV is influenced by the battery charging/discharging. In order to maintain the exact battery sustainability, dynamic programming, a kind of global optimization strategy, is applied offline to derive the optimal solutions with minimal engine fuel consumption and exact battery SOC balance. The mode switching rules are further extracted and used to decide the operation modes for real-time control applications. The operation efficiencies of different components are analyzed, and the system transmission efficiency for the operation mode that both the engine and electric machines are engaged in is obtained. Then, the optimal problem based on model predictive control scheme is constructed with the objective of maximal powertrain transmission efficiency. The optimal problem in the prediction horizon is solved by dynamic programming to obtain the optimal control sequence. Finally, simulation studies are made. Simulation results demonstrate that the transmission efficiency oriented predictive strategy can maintain the battery charging sustainability and improve the equivalent fuel economy of the HEV effectively. The results validate the feasibility and superiority of the proposed controller.