Research On Energy Management Of Hybrid Energy Supply System Of Fuel Cell And Auxiliary Power Supply

Hydrogen energy is one of the ideal solutions for achieving carbon neutrality.Electric vehicles with hydrogen as the main fuel have the advantages of zero pollution,zero carbon emission,short refueling time,and high energy density.However,hydrogen fuel cells also have deficiencies such as slow dynamic response to load changes,unable to recover energy,etc.Therefore,auxiliary energy needs to be configured to form hydrogen electric hybrid energy supply system.In the design of hydrogen-electric hybrid energy supply system,the energy distribution strategy of fuel cell and auxiliary energy is particularly important.In order to carry out targeted research on energy allocation strategies,this paper firstly conducts a comparative selection analysis on the topological structures of different hybrid energy supply systems,and finally determines the structure（FC+B）with proton exchange membrane fuel cell（PEMFC）as the main energy source and lithium ion battery as the auxiliary energy source as the research model of this subject.The model of hydrogen electric hybrid energy supply system of this structure was built in MATLAB/Simulink platform,and its key components were simulated and verified.This thesis proposes and compares two different energy management strategies for FC+B hybrid energy supply system.One is to realize energy management control by determining rules,which mainly combines load demand power(P_req),fuel cell system power(P_FC)and State of Charge（SOC）of lithium-ion battery system.14 different control rules are formulated to complete the regulation and control of dynamic power distribution.The other is the improved fuzzy logic control energy management strategy.Based on the fuzzy control strategy which takes the lithium-ion battery system SOC and load demand power Preq as dual input sources and the fuel cell power distribution coefficientαas output,the sub-fuzzy rule controller is designed considering the negative value of load power demand during operation.A fuzzy logic energy management strategy based on dual fuzzy controllers is proposed.Aiming at the above two different energy management strategies,this thesis selects the New European Driving Cycle（NEDC）for simulation verification and comparative analysis on the MATLAB/Simulink simulation platform based on the self-built hybrid hydrogen and electric energy supply system model.The research shows that the two energy management and distribution strategies proposed in this paper can both meet the power demand in the simulation condition.When the initial SOC₀ of the lithium-ion battery is low or high（SOC₀=39%and SOC₀=82%for example）,the energy management strategy based on fuzzy rule control can make the lithium-ion battery more stable in the ideal SOC working range.In the thesis,the research on the energy distribution strategy has a certain reference value for the application of hydrogen-electric hybrid energy supply electric vehicle.