Research On Air Control Strategy Of Fuel Cell Test Platform

Fuel cell is an important development target to realize the low-carbon energy strategy,and it is one of the most promising power generation technologies at present.As a product for evaluating the performance of fuel cells and testing the life of fuel cells,the fuel cell test platform functions in multiple links such as fuel cell research and development,production,and quality inspection.The development of fuel cell testing technology will greatly promote the product iteration of fuel cells.This thesis studies the air supply system,one of the most important subsystems in the test platform.The specific research contents are as follows:1.Analyze the regulation requirements of the air supply system of the fuel cell test platform and propose a system design scheme.Firstly,the influence of the air supply system on the output performance of the stack was analyzed by theoretical analysis combined with the experiment method.Then,based on the demand of the air supply system,the flow control equipment and back pressure valve in the system were selected and analyzed.According to the selection results,the air supply system scheme of the fuel cell test platform is designed.2.A simulation model of the air supply system including proportional valve model,throttle valve model,supply manifold model,stack flow consumption model and cathode flow model is established.Combined with mechanism modeling and data-driven modeling,the proportional valve model and throttle valve model in the air supply system are established,and the correctness of the model is verified by comparing the experimental data with the simulation results.In addition,the supply manifold model,the stack flow consumption model and the cathode flow channel model are established by the method of mechanism modeling.3.To meet the high-precision regulation requirements of the fuel cell test platform air,the control strategies based on the PID algorithm and the feedback linearization algorithm were studied respectively.Firstly,the air supply system model is used to simulate and analyze the coupling relationship between flow and pressure in the system and the disturbance effect of load current on the system.According to the analysis results,the thesis uses the PID algorithm to design a controller to simulate the control effect.The simulation results show that the PID control makes the system reach the expected steady state,but the system output deviates greatly during the dynamic change process.Then,the feedback linearity is used on this basis.The nonlinear system is transformed into a linear system,and the dynamic change process of the system is successfully optimized.The final comparative analysis shows that,compared with PID control,the deviation values of air flow and air pressure under feedback linear control are respectively reduced by 77.9% and 86.9 %,which realizes the decoupling control of the air supply system,and adjusts the load current to the system.Disturbances in flow and pressure are respectively reduced by 60.7 % and 43.6%.