Research On Control Of Fuel Cell Power Generation System

Fuel cell,as a new type of green energy,has the advantages of no pollution,zero emission,high system reliability,strong environmental adaptability and high power density compared with traditional fossil energy.Among different kinds of fuel cells,proton exchange membrane fuel cell(PEMFC)occupies the dominant position in the current market due to its advantages of high fuel conversion efficiency,no waste emission and low requirement for working environment compared with other types of fuel cells.Although fuel cells have many advantages,there are some disadvantages in fuel cells:the volt-ampere output characteristics of fuel cells are weak;the energy conversion efficiency of fuel cells will decrease because of the fluctuation of the output power and affect the service life of fuel cells.How to overcome the two major shortcomings of fuel cell and improve the output characteristics of fuel cell power generation system has become a key issue.Based on the current research hotspots of proton exchange membrane fuel cells,the optimization and control of fuel cell power generation system are studied in the following aspects.Based on the analysis of the working principle,electrical and electrochemical characteristics of fuel cell,the input-output dynamic response mathematical model of PEMFC system is established.By comparing the response curves obtained from the model simulation with those measured by PEMFC,it is confirmed that the model is basically consistent with the actual dynamic characteristics of PEMFC.That is,the PEMFC system model can effectively reflect the dynamic changes of PEMFC system performance,which lays a foundation for future research on fuel cells.Based on the electrical characteristics of fuel cells,a maximum power tracking control method for fuel cells is proposed.The simulation results show that the proposed maximum power tracking algorithm can achieve the maximum power tracking of fuel cells under different working conditions,and has the advantages of simplicity,rapidity,accuracy and strong environmental adaptability.It can give full play to the efficiency of fuel cell power generation system,improve the efficiency and durability of fuel cells,and has good practical value.Based on the characteristics of slow dynamic response and poor anti-disturbance ability of fuel cell power generation system,according to the control rules of extension control and fuzzy-PID control,extension control and fuzzy-PID control are respectively applied to the tracking control of output current of fuel cell power generation system to improve the dynamic response ability of fuel cell system.Through the comparison of simulation results,it is found that the robustness of extension control is better than that of fuzzy PID control,and it has better regulation ability and dynamic characteristics.