Dynamic Response Analysis And Life Prediction Of Proton Exchange Membrane Fuel Cell

Durability is the key factor to restrict the commercial application of fuel cell in the field of transportation.One of the most important characteristics of vehicle fuel cell which is different from other applications is frequent load change,and the durability of fuel cell is greatly affected by frequent load change.Therefore,it is of great significance to study the response characteristics of fuel cells under different dynamic loads,improve the response ability of fuel cells to load changes,and predict the remaining life of fuel cells under different dynamic conditions for improving the actual service life of fuel cells and accelerating the large-scale commercial application of fuel cells.In this paper,a one-dimensional simulation model of PEMFC system is established on the MATLAB /SIMULINK simulation platform.The start stop and load change process of PEMFC is simulated.The influence of operation parameters and load change parameters on the dynamic response characteristics of the battery voltage is analyzed.Based on this,the response strategy to improve the dynamic response characteristics of the fuel cell is proposed.Finally,combined with the actual operating conditions of the fuel cell,the service life of the fuel cell is predicted.In view of the influence of various polarization losses on the output voltage of fuel cell,the response performance of thermodynamical electromotive force,ohmic electromotive force,activation electromotive force and concentration electromotive force to the change of load current is studied.It is found that the activation electromotive force and ohmic electromotive force are the main factors that affect the response speed of fuel cell voltage in the start-up condition,and the voltage response speed in the stop condition It is found that the smaller the load change amplitude and the slower the load change speed,the better the response of the fuel cell voltage to the load current,and the higher the gas pressure and the operating temperature The moisture content and gas excess coefficient in the membrane can improve the dynamic response characteristics of the voltage.Based on the study of the dynamic response characteristics of fuel cell voltage under different working conditions,the measures to improve the dynamic response capability of fuel cell are proposed,such as increasing gas supply scheme,temperature change scheme,etc.,and the particle swarm optimization algorithm and PID control are combined to improve the stability and response characteristics of the battery voltage by controlling the hydrogen flow.Based on the voltage degradation rate model,the remaining service life of the fuel cell under different working conditions is predicted.Through quantitative analysis,it can be seen that frequent load change and start-up and shutdown will significantly reduce the remaining service life of the fuel cell.In order to avoid the cost waste caused by blindly pursuing the long life of fuel cell,the cost life of fuel cell under different working conditions is predicted,and the service life under the minimum cost value is obtained,which has certain reference value for reducing the cost of fuel cell.