Analysis Of Output Characteristic And Research On State-of-Health Monitoring For PEMFC

PEMFC(Proton Exchange Membrane Fuel Cell) possesses someadvantages,such as no pollution,low startup temperature,high energy efficiency andso on.In addition to widely used in portable equipment,it can also be used incars,buses,and cogeneration systems,which has been a hot research spot in fuel celltechnology.However with the development of fuel cell power generationtechnology,there have been some bottleneck problems,for example:how to realize thestack optimal control and optimize output performance aimed at the operatingconditions of stack have become a hot problem to be solved.Based on V-I and EIS(Electrochemical Impedance Spectroscopy) methods, Thispaper researches the output performance of water-cooling PEMFC,and a health statusdiagnosis method based on the characteristic of stack impedance parameters isdesigned,the specific contents are as follows:(1) Based on the power generation principle and characteristics of PEMFC,thispaper comprehensively analyze the stack electrochemical reaction process, and asuitable equivalent circuit of PEMFC has been built.Furthermore,in order toexpediently carry out the later data fitting, the impedance model is simplified,at thesame time,based on the mechanism research, this paper analyze the relation betweenthe impedance parameters in different polarization segment and the outputperformance of the stack.(2) According to the mechanism research results and the need of experimentalresearch,a experimental system of water-cooling PEMFC stack output performanceand a PC detecting and controlling procedure have been designed,which can realizethe stack operating condition control and the voltage, current and impedance datadetection of the stack at runtime.(3) The V-I and EIS experiments varying operating conditions are carried out onthe water-cooling PEMFC, According to the activation polarization,ohmicpolarization and concentration polarization of the stack, combined with the V-Icharacteristics method and EIS method, the experimental results are analyzed and summarized, obtaining the influencing regularities of the change of operatingconditions on internal stack hydrothermal status and the output performance.(4) Based on the experimental research results, a water health status monitoringmethod of the PEMFC output performance is designed, also the simulation is carriedout to verify the algorithm in Matlab, the results show the validity of the monitoringmethod.