Study On Voltage Uniformity And Fault Analysis Of Self-humidifying Air-cooled PEMFC

With the development of technology and depletion of the global fossil energy,the new energy technology has attracted more and more attention.Proton Exchange Membrane Fuel Cell(PEMFC)has been widely used in distributed power supply,transportation,aerospace and aviation because of its high energy density,fast start-up speed,low noise and zero emission of exhaust gas.However,due to the high cost of production and short service life,the commercialization of PEMFC has been greatly restricted.Therefore,in order to improve the working life of PEMFC and ensure the efficient,safe,stable and long-term operation of PEMFC system,it is of great significance to study the running state and fault diagnosis of PEMFC.Firstly,the structure,principle,water migration mechanism and characteristics of self-humidifying air-cooled PEMFC are introduced in this paper.And a dynamic model of PEMFC is built based on MATLAB/Simulink.The thermodynamic model is improved by knowlage of mass transfer and heat transfer theories and mechanism model of fuel cell.And the temperature response of PEMFC under different fan's power is simulated.The simulation results show that the model has good simulation ability in steady-state voltage output response,temperature response and dynamic voltage output response,etc.Secondly,the voltage characteristics,temperature characteristics,stability and uniformity of self-humidifying air-cooled PEMFC,which is developed by Temasek Polytechnic Clean Energy Research Center of Singapore and Duralitepower Company,were studied experimentally.The effects of load current and fan's power on voltage uniformity of the stack are analyzed emphatically during the steady-state operation.The experimental results show that the voltage uniformity will deteriorate with the increase of load.The main reasons for this phenomenon are the uneven distribution of internal resistance and surface temperature.The influence of fan power mainly depends on whether the cooling capacity provided by the fan can meet the demand of the stack cooling.Finally,this paper designs simulation experiments of common water faults including flooding and membrane dehydration based on the characteristics of self-humidifying air-cooled PEMFC.Firstly,the sensitivity of the experimental data to faults is analyzed,and appropriate eigenvalues are selected according to the characteristics and sensitivity of the data.Secondly,the effects of load current and fan power on the degree and the deterioration rate of flooding are analyzed.Finally,according to the flooding experiment and high temperature experiment,a fault diagnosis method for self-humidifying and air-cooled PEMFC is designed.