Research On Energy Management System Of Fuel Cell Vehicle Based On Multi-objective Optimization

With the increasingly serious environmental problems and the adjustment of China’s energy structure,new energy vehicles have attracted more and more attention in recent years.Fuel cell vehicles(FCV)have different advantages over fuel vehicles and pure electric vehicles,which is an ideal development direction of new energy vehicles.At present,FCV generally adopts a hybrid drive scheme with multiple energy sources,and uses energy management strategy(EMS)to realize the power distribution among the energy sources.It is of great significance to develop a reasonable EMS to improve the performance of the power system and its key components for the application and promotion of fuel cell vehicles.This paper studies the energy management strategy of fuel cell hybrid electric vehicle,in order to improve the hydrogen fuel economy of vehicle and the durability of fuel cell.The specific research contents are as follows:(1)According to a hybrid structure of fuel cell and battery pack,the vehicle dynamics model and the model of key components of fuel cell vehicle are established,including the efficiency model of fuel cell,battery and DC/DC converter,so as to provide assistance for the calculation of equivalent hydrogen consumption.(2)According to the power flow of fuel cell vehicle hybrid system,the method of converting the actual energy consumption into hydrogen consumption is adopted to propose an accurate equivalent hydrogen consumption model of the power system;according to the mechanism of life decay of fuel cell,the performance decline under typical load changing conditions is studied,and the calculation method of remaining available life based on load change is proposed.(3)According to the analysis of the power state of the fuel cell vehicle power system and the characteristics of each energy source,the design principle of energy management strategy is determined.The control method based on fuzzy logic is used to realize the power distribution of each energy source.The simulation results based on advanced vehicle simulator(ADVISOR)show that the designed control strategy meets the requirements of energy management.(4)In order to improve the proposed energy management strategy,a multi-objective optimization problem with equivalent hydrogen consumption and remaining service life of fuel cell as optimization objectives was proposed,and an improved non-dominated sorting genetic algorithm(NSGA-II)was used to solve the approximate optimal solution set.The optimization process of the algorithm is designed,and the optimization results of the above algorithm are simulated.Through ADVISOR platform,the optimized strategy and other strategies are simulated under certain cycle conditions.The results show that the optimization is effective,the quality of the population of the algorithm has been significantly improved,and the optimized control strategy has better performance than the common rule-based strategy and the non optimized fuzzy control strategy.