Energy Management And Operation Energy Efficiency Improvement Method For Fuel Cell Hybrid Urban EMUs

In order to promote the development of a clean,low-carbon and high-efficiency rail transit energy power system,hydrogen fuel cell hybrid trains have gradually become a new development trend of rail vehicles due to their high efficiency,environmental protection,and zero pollution.In order to improve the transportation capacity of the city center city and surrounding new cities or towns in group cities,this paper takes the fuel cell hybrid electric EMU as the research object,reasonably configures the number of fuel cells and lithium batteries,and formulates different types of energy management methods to improve power System output performance,research methods to improve the energy efficiency of train operation,reduce hydrogen consumption during train operation,and provide new ideas for the development of urban railways.The main work of this paper is as follows:Based on the dynamic model and main technical parameters of the urban EMU,the traction characteristics,braking characteristics and peak speed of the train at different gradients are calculated and analyzed.The working characteristics of different fuel cell hybrid power system configurations are analyzed,and the power system configuration suitable for urban EMUs is selected.The required power and energy of the train under possible extreme conditions are solved,and the output power constraints of the hybrid power system and the capacity constraints of the lithium battery are obtained.According to the train size and axle load constraints,the load capacity constraints are obtained.The number of configurations of fuel cells and lithium batteries.Based on MATLAB/Smulink,a fuel cell hybrid system model for municipal EMUs was built,and a semi-physical test platform was built based on the RTLAB real-time simulation system,which laid the foundation for the experimental test of the power system of municipal EMUs.According to the output characteristics of the fuel cell and lithium battery,the electrichydrogen conversion model of the fuel cell hybrid power system is established.In order to reduce the hydrogen consumption of the fuel cell hybrid system,maintain the state of charge(SOC)of the lithium battery and improve the working efficiency of the fuel cell,a dual-mode energy management method considering the optimization of the fuel cell efficiency interval is proposed.of the hybrid power system considering the optimization of the fuel cell efficiency range Energy management method,ER-DEM),in this method,the lithium battery SOC management strategy is used as the first-level mode,and the fuel cell efficiency range is optimized as the second-level mode to realize train running.In the process of real-time management of fuel cells and lithium batteries.The experimental results show that the method proposed in this paper can effectively distribute the output power of the power system and restrain the SOC of the lithium battery within the target value field,reduce the total hydrogen consumption of the power system,improve the working efficiency of the fuel cell,and realize the real-time management of the hybrid power system.,laying the foundation for improving the energy efficiency of vehicle operation.Aiming at the different traction energy consumption caused by different driving speeds in the urban EMU station and the energy loss caused by the different output of the hybrid power system,a fuel cell hybrid urban EMU operation energy efficiency improvement method is proposed.This method comprehensively considers the traction,braking characteristics,line information and traction drive system efficiency of urban EMUs,takes the minimum train traction energy consumption as the goal,and uses the train position,speed and speed limit as state variables to establish a train running state model.The principle of large value is used to solve the control variables and co-state variables of the urban EMU under the four driving states of acceleration traction,constant speed traction cruising,inertia driving and braking and deceleration.The train interval speed optimization curve,traction power curve and The traction energy consumption curve is optimized,and the output of the fuel cell hybrid power system is optimized to achieve the improvement of energy efficiency during the operation of urban EMUs.The experimental results show that the traction energy consumption of urban EMUs is reduced by 7.38% and the hydrogen consumption is reduced by 3.73% under the same line information conditions,which improves the working efficiency of fuel cells.Therefore,the method proposed in this paper can improve the efficiency of fuel cell hybrid electric urban EMUs.Operational energy efficiency.