Research On Fuel Cell Bus Power System Parameter Matching And Energy Management Strategy

Fuel cell vehicles powered by fuel cells have become one of the directions of development for new energy vehicles due to the advantages of high energy conversion efficiency and zero emission pollution of fuel cells.However,due to the disadvantages of slow power dynamic response and unidirectional output,fuel cells need to be combined with auxiliary energy storage devices(power batteries,etc.)to serve as the energy source for fuel cell vehicles.Therefore,the development of a reasonable energy management strategy has become a key issue for research in the field of fuel cell vehicles.(1)Parameter matching of fuel cell bus powertrains.In this paper,fuel cell bus is taken as the research object,firstly,from the fuel cell bus energy source,the structural characteristics of the main energy sources were analyzed,the technical solutions of the fuel cell bus energy system were selected and designed,and the semi-active type(fuel cell connected to the bus via one-way DC/DC)was chosen as the power system structure of the fuel cell bus.According to the vehicle parameters and design performance index,the fuel cell bus energy power system was selected and matched with parameters,which included fuel cell,power cell and drive motor.(2)Construction of a complete vehicle simulation platform.Based on the selection and matching results of the fuel cell bus power system structure and main components,the whole vehicle simulation platform of the fuel cell bus was built based on MATLAB/Simulink,including seven modules of test conditions,driver,control system,fuel cell,power cell,drive motor and vehicle dynamics,and the functions and modelling principles of each sub-module were introduced in detail.(3)Development of energy management strategies.The energy management strategy in this paper aims to achieve a reasonable and effective distribution of power between the fuel cell and the power cell to further reduce hydrogen consumption,maintain efficient fuel cell operation and extend service life.In this paper,three energy management strategies were developed,namely rule-based strategy,the proposed solution of the maximum and minimum power of the power cell according to the predicted power,the upper and lower range of the state quantity SOC in advance,the developed predictive control based on the improved DP and the proposed data grid of the fuel cell power cluster and the vehicle demand power cluster,and the energy management strategy of the predictive control based on the game theory,and the S-function was written for the strategies through MATLAB,and the energy management strategies were simulated in the vehicle simulation platform using the S-function module.(4)Simulation of energy management strategies for comparative analysis.The rule-based,improved dynamic programming-based predictive control and game theory-based predictive control energy management strategies were compared and analyzed in terms of hydrogen consumption,final SOC value and average fuel cell efficiency under the Chinese city bus driving conditions(CHTC＿B).The parameters of the improved DP-based predictive control strategy and the game theory-based predictive control strategy are compared and the best values were selected.The results show that the game theory-based strategy has the best overall control effect.For hydrogen consumption,the rule-based strategy,the improved DP-based strategy and the game-theoretic-based strategy were 0.39 kg,0.16 kg and 0.33 kg respectively,where the gametheoretic-based strategy improved fuel cell efficiency at the expense of hydrogen consumption,with an average efficiency of 58.7%;constrained fuel cell power fluctuations,with an average fluctuation of 1057.2W;The fuel cell start-stop cycle was controlled and the number of fuel cell starts and stops and the percentage of shutdowns within a single operating condition were both0;the ability to extend fuel cell life was improved by 46% compared to the rule-based strategy.