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

The proton exchange membrane fuel cell is an energy conversion device that generates electrical energy by electrochemical reaction of fuel and oxidant.(1)It has the advantages of high energy density,high working efficiency,low working temperature,fast response and stable operation.It is suitable for mobile power,new energy vehicles and distributed power generation,and has great potential for development.This paper mainly focuses on the mathematical modeling of PEMFC system,the control of gas supply system and the design of PEMFC monitoring system.mainly include:(2)According to the basic structure and working principle of PEMFC,the mathematical models of PEMFC voltage subsystem,cathode air supply system subsystem,anode hydrogen supply subsystem,humidifier subsystem,air compressor and cooling subsystem are established respectively.And use Matlab/Simulink to build PEMFC system simulation platform.(3)In order to make the PEMFC system output higher and more stable net power,the PEMFC gas supply system control method to study.Aiming at the problem of Oxygen Excess Ratio(OER)in PEMFC system,PID controller and fuzzy controller were used to control the air compressor voltage to adjust the OER in the cathode.(4)Select the fuzzy controller to control the air compressor operating voltage.In order to solve the problem that the expert experience is not accurate enough,this paper uses particle swarm optimization to optimize the rule and rule weight of fuzzy rule base respectively.The simulation results show that the optimized accuracy of the fuzzy controller is improved,the OER curve is approximately coincident with the ideal value curve,and the working voltage fluctuation of the air compressor is obviously reduced and the net output power of the system is improved.(5)In order to avoid the proton exchange membrane anode and cathode pressure difference on both sides of the exchange membrane bending stress,the use of PID controller to adjust the flow of anode hydrogen.The simulation results show that the pressure difference between the anode and the cathode is almost absent.The hydrogen Excess ratio(HER)is close to 1,and the hydrogen flow into the anode is completely consumed by the electrochemical reaction.In order to better analyze the dynamic characteristics of PEMFC system and to better adjust its control method,it is very important to establish PEMFC monitoring system.The monitoring system is mainly composed of PC monitoring terminal,main control system and battery voltage detection system.The main function of the main control system is through the multi-channel sensor to collect PEMFC system information parameters and after processing through the CAN network to the host computer and accept the host computer control instructions to achieve the PEMFC system regulation.