Research On The Power System And Energy Management Strategy Of Fuel Cell Vehicle

With the adjustment of the national energy strategic structure,the long-term problem at present and in the future is the transformation from conventional fuel vehicle to green new energy vehicles.Hydrogen energy has a series of advantages,such as zero emission,high energy conversion efficiency,easy access,renewable and so on.Therefore,fuel cell vehicles have gradually become the future development direction of new energy vehicles.However,restricted by the existing technology of fuel cell,there are still many obstacles to the commercialization and popularization of fuel cell vehicles.At present,the short board problem of fuel cell is that the output voltage and current characteristics are soft,the dynamic response speed is slow,the starting speed is slow,and the braking energy cannot be absorbed.Auxiliary energy is added into the power system of fuel cell vehicle to reduce the peak value of fuel cell output power and fill its trough,so that the fuel cell can still meet the requirements of vehicle performance under normal conditions.The power and economic performance of vehicles are directly affected by the power system structure and energy management strategy of fuel cell vehicles.Therefore,the design of fuel cell vehicle power system and energy management strategy has very important research significance.The first part introduces the development and research status of fuel cell at home and abroad.By comparing the complementary structures of the four power systems,the fuel cell + battery power system is finally selected for energy selection,the main energy of the fuel cell is proton exchange membrane fuel cell,and the iron phosphate-lithium battery is used as auxiliary energy.Thevenin equivalent model of fuel cell and the internal resistance model of battery are selected to model and analyze the main power source and auxiliary power source.In order to ensure a more reasonable distribution of output power of cells and fuel cells and maximize the advantages of hybrid power system.Therefore,a simulation model based on fuzzy control strategy is built in MATLAB/Simulink.Aiming at the problem that fuzzy control depends on expert experience and is too subjective,the membership functions of fuzzy rules and fuzzy control are optimized and parameterized by genetic algorithm,and the fuzzy control strategy optimized by genetic algorithm is obtained.Based on AVL CRUISE platform,the pure fuel cell power system simulation model fuel cell + battery power system simulation model are built.The fuzzy control strategy and the fuzzy control strategy optimized by genetic algorithm are jointly simulated based on NEDC and WLTC working conditions.The data results show that the designed fuel cell vehicle power system and energy management strategy are feasible,and the test shows that the power performance of the whole vehicle meets the design requirements,and the economy is also improved.