Research On Energy Management Strategy Of Hybrid Electric Locomotive Based On Multi-variable Fuzzy Control

In the background of global low-carbon energy,sustainable development strategies such as low-carbon travel,energy conservation and emission reduction are vigorously advocated by the government.As hydrogen is rich in resources,green and low-carbon,etc,hydrogen energy technology is the best choice for china to achieve large-scale decarbonization in various fields such as transportation,industrial production,and construction.Because fuel cells achieve high power output in recent years,hybrid technology and energy management strategies have also begun to develop in the field of rail transportation,industry production,building construction and so on.In this paper,through the modeling and performance simulation of fuel cell-battery hybrid locomotive,and the application of multi-variable fuzzy control strategy,the energy management strategy of hybrid power system under different working conditions is explored to optimize the performance of hybrid locomotive.The main work of this paper is as follows:1.Selection and parameter matching of various components of the hybrid locomotive.Through a comprehensive comparative analysis of the working principles,performance advantages and economy of the fuel cell,battery and motor,combined with the operating characteristics of the hybrid locomotive,the proton exchange membrane fuel cells and lithium batteries are selected as power sources,and a hybrid system topology in which both fuel cells and lithium batteries are indirectly connected to the traction inverter is adopted.By calculating the maximum required power,the parameter matching of the fuel cell and the battery is completed.2.Vehicle modeling of hybrid electric locomotive.The proton exchange fuel cell model,lithium battery model,one-way DC/DC converter model,two-way DC/DC converter model,permanent magnet synchronous motor model,dynamic model are established,and the property of each component are simulated and analyzed.The working characteristics of the hybrid electric locomotive have been completed,and the starting conditions of the hybrid locomotive have been simulated.3.Research on energy management strategy of multi-variable fuzzy control.According to the different power requirements of hybrid locomotives during operation,a multi-variable fuzzy controller with two inputs and two outputs is established.Inputs of fuzzy control are the maximum state of charge of the lithium battery and the required power of the locomotive,and outputs of fuzzy control are the current density of the fuel cell(corresponding to control the output power of the fuel cell)and the state of charge of the lithium battery(corresponding to the control of the output power of the lithium battery).The multi-variable fuzzy controller is applied to the hybrid electric locomotive model,and the starting condition of the hybrid electric locomotive is simulated for the feasibility verification of the fuzzy control.On this basis,the simulations for the working conditions of acceleration stage from 40km/h to 60km/h,40km/h to 80km/h,40km/h to 100km/h,and the deceleration stage from 100km/h to 80km/h and 100km/h to 60km/h,100km/h to 40km/h are carried out,the distribution of output power between fuel cells and lithium batteries and the time required to reach actual steady vehicle speed.The simulation results show that the multi-variable fuzzy controller can control the operation of the hybrid locomotive well,which verifies the feasibility of the multi-variable fuzzy controller.