Research On Combined Flow And Pressure Control Of Automotive Fuel Cell Air System

In the context of the increasingly serious energy crisis and environmental pollution,achieving green and low-carbon transformation of energy is a necessary path for sustainable development.As one of the main sources of carbon emissions,the automotive industry has gradually transformed towards sustainable and intelligent transportation with green power as its core,leading to rapid development of new energy vehicles powered by proton exchange membrane fuel cells(PEMFC)and other technologies.However,in the complex and variable vehicle operating conditions,such as frequent changes in power demand,the dynamic response ability of PEMFC needs to be improved,and the air system of the fuel cell plays a dominant role in affecting the dynamic performance of the fuel cell.Therefore,efficient and accurate control of the air system is a necessary prerequisite for ensuring the sustained and stable operation of fuel cell vehicles.This article aims to improve the dynamic response ability of the fuel cell air system and conducts related research on the dynamic operating conditions of the air system through simulation analysis and experimental testing.The main work content is as follows:(1)To address the issue of the impact of cathode inlet parameters on PEMFC,a three-dimensional numerical model was used to simulate and obtain the internal characteristics of the PEMFC,the internal characteristics of the PEMFC were obtained;By analyzing the changes in cathode inlet gas parameters,the impact on the cell’s output performance,internal material distribution,membrane characteristics,and other properties were studied.It was concluded that the flow rate and pressure of the cathode inlet have an effect on the performance of the PEMFC.(2)This study focused on the aerodynamic characteristics of the air system of a commercial vehicle equipped with an 80 k W fuel cell stack.An experimental platform was built,and the air system was tested.The necessary sensors in the system were tested and verified to clarify the control response characteristics of the controlled components.Through multiple tests,the aerodynamic characteristics of the air system were obtained.Combining the actual requirements of the stack,the structure of the platform,and the impact of the cathode inlet parameters on the performance of the fuel cell,the relationship curve between the air system’s input parameters and the stack current was obtained and analyzed.At the same time,the control variables of the air system’s joint control algorithm were determined.(3)To address the complex and strong coupling issues of the air system,based on existing research,an internally decoupled current gain-based joint control algorithm for flow rate and pressure of the air system was designed,which is oriented towards engineering practicality.Through related testing,the parameter values of the control module were obtained.With the experimental platform already built,continuous dynamic response tests under variable loads were conducted to verify the good control performance of the designed algorithm in dynamic operating conditions.Through the above work,this paper systematically investigates the characterization of the influence of flow and pressure on the cathode inlet of PEMFC,the aerodynamic characteristics of the air supply circuit,the relationship between the demand characteristics of the reactor cathode inlet parameters and the design of the joint control algorithm of the air system,from the three-dimensional numerical mechanism model of PEMFC to the actual system experimental bench,from the analysis of the influence of the cathode inlet parameters of the battery body to the air system bench test verification.The results of the study show that the cathode inlet of the PEMFC is a very important part of the cathode control.The results show that: the cathode inlet flow and pressure should be gradually increased with the rise of load,but under different loads,the flow and pressure should be increased by a certain limit,which can effectively reduce the energy consumption of pressurized auxiliary parts and the mechanical load of PEMFC while ensuring the output performance of PEMFC;for the continuous dynamic variable load condition,the designed control algorithm is applied to the air system bench,and the transient response time of the cathode inlet flow and pressure of the reactor is reduced.The designed control algorithm is applied to the air system bench and has good control capability on the transient response time and stability of flow and pressure,which proves the real-time effectiveness and reliability of the control module.