Research On Modeling And Control Of Proton Exchange Membrane Fuel Cell System

The proton exchange membrane fuel cell works by hydrogen reacting with oxygen producing water and heating,which has the characteristics of no pollution,high energy density and high working efficiency,one of the most effective methods to solve the energy shortage and environment pollution,is increasingly the focus of attention in car manufacture.The control goal of fuel cell system is to improve output of net power of PEMFC.Some articles and experiments indicate promoting the net power is associated with improving the oxygen excess ration,which is the oxygen flow rate of entering the cathode divided by the oxygen flow rate of reaction comsuption.Because oxygen is pumped into fuel cell system by compressor,controling the compressor voltage can achieve control goal.The main results are as follows:(1)The simulation platform,which is based on the electrochemical reaction mechanism and basic structure of PEMFC,is built in Matlab/Simulink.The models mainly conclude electrochemical reaction,air supply system,hydrogen supply system and other auxiliary equipments.The simulation platform is prepared for testing proposed control methods.(2)In order to improve the output of net power,in this paper the control methods to compressor working voltage are disscussed.Firstly,based on the deviations of actual oxygen excess ratio and ideal oxygen excess ratio,the PI control method is adopted to adjust the compressor working voltage.And then genetic algorithm is used to optimize the parameter of PI controller.In order to solve response delay issue of PI controller,the fuzzy controller is used,then the method is changed,combined fuzzy control with PI control,which makes the conrol method undisturbed.At last,adopted GA optimizes membership function,and operate simulation model.(3)The GA-Fuzzy-PI control method is tested based on the hardware-in-the-loop experimental platform.The platform is concluded dSPACE,ETAS.ES910,ETAS.ES930,compressor and other equiments.Downlod the buildt simulation model to dSPACE and downloadthe control method to ETAS.ES910,and then conduct the experiment.(4)According to the vehicle parameter and dynamic parameter,the parameter of motor,fuel cell and battery can be calculated.In order to guarantee excellent output performance of PEMFC,the fuzzy control is adopted to attain given goals.