Research On Energy Management Control Strategy Of Fuel Cell Hybrid Vehicle

Energy-saving and new energy vehicles are an important development direction in China’s "dual carbon strategy".Among them,fuel cell vehicles are considered to be one of the promising directions for development due to their zero emission and high efficiency.However,at this stage of research,the cost of fuel cells is relatively high and key technologies have not yet been broken through,such as slow cold start,inability to recover braking energy,poor output characteristics,etc.At present,the above problems are mainly solved by using hybrid power systems of fuel cells and other power sources.The hybrid power system makes the power distribution and energy flow of the whole vehicle more complex,therefore,a reasonable energy management control strategy is proposed to give full play to the advantages of the hybrid power system.In this paper,the fuel cell hybrid electric vehicle(FCHEV)is used as the main energy source and the power cell as the auxiliary energy source,and the total hydrogen consumption and battery life of the hybrid system are the objectives of the study.Firstly,the powertrain transmission scheme of the fuel cell hybrid vehicle is designed,followed by the selection and parameter matching of fuel cell,power cell and drive motor components in the powertrain according to the dynamics parameters of the whole vehicle,and then the powertrain model and the longitudinal dynamics model of the whole vehicle are built based on AVL Cruise software.Secondly,an improved fuzzy logic energy management strategy is proposed.The designed fuzzy controller takes the whole vehicle demand power and power cell SOC as input and the fuel cell output power as output.According to the characteristics of fuel cell and power cell hybrid power system,the switching control strategy is loaded into the conventional fuzzy controller and the fuzzy control rules are modified by considering the fuel cell life and efficiency under low load conditions.In the Matlab/Simulink-based simulation platform,two operating conditions,NEDC and WLTP,are loaded.The simulation results show that the improved fuzzy control energy management strategy reduces the total hydrogen consumption by 23.74% and 12.36% respectively compared with the conventional fuzzy control energy management strategy,and the SOC is maintained within a reasonable range,which effectively improves the economy of the whole vehicle and the durability of the fuel cell.Finally,to address the errors and limitations of the fuzzy control energy management strategy,the subordination function of the fuzzy controller is further optimised by combining the dung beetle optimisation algorithm with the objective of reducing hydrogen consumption,and the optimisation objective function and constraints are constructed.The conventional fuzzy control energy management strategy,the improved fuzzy control energy management strategy and the fuzzy control energy management strategy based on the dung beetle optimization algorithm are simulated and compared to achieve a reasonable distribution of power between the fuel cell and the power cell and maintain the power cell SOC in a certain range while satisfying the demand power.The results show that under WLTP conditions,the fuzzy control energy management strategy based on the dung beetle optimisation algorithm reduces the total hydrogen consumption by 13.47% and 1.26% respectively compared to the conventional fuzzy control energy management strategy and the improved fuzzy control energy management strategy,further improving the overall vehicle economy.