Study on Parameter Optimization of Energy Management Strategy for Multi-mode Hybrid Power Bus

The research on parameter optimization and energy management strategy is carried out based on a hybrid electric bus with multi-mode switching structure. A three-stage transmission is equipped on the motor side, the gearbox shifting strategy is formulated according to the technical experience preliminarily, and the hybrid bus simulation model and energy management strategy model are established based on MATLAB / Simulink. Taking the equivalent fuel consumption per 100 kilometers of the NEDC cycle as the optimization objective function, the multi-mode switching parameters and the transmission ratio are optimized by using the direct mode search algorithm. The results show that the designed control strategy can make the engine mainly work in the low fuel consumption range. Compared with the single-speed ratio, the three-stage speed ratio can improve the motor operating points and reduce the engine operating points in the low power and high fuel consumption area. Compared with the basic case, after parameters optimization, the total fuel consumption per 100 km of the NEDC cycle is reduced by 5.0%, and the internal combustion engine fuel consumption per 100 km of the NEDC cycle is reduced by 4.8% if using the three-stage transmission.