Research On Control Of Water Cooled PEMFC Thermal Management System

Energy shortage and environmental pollution are the main problems facing the world today.Developing and utilizing clean energy and renewable energy,adjusting energy structure and reducing harmful gas pollution to the environment have become an important part of the sustainable energy development strategy of all countries in the world.The main product of Proton Exchange Membrane Fuel Cell(PEMFC)is water.Its reactants and products are not polluting.If Pem FC can replace fossil energy and be widely used,the problem of environmental pollution and energy shortage will be solved easily.However,when PEMFC is in operation,it generates a lot of heat,which raises its internal temperature.When the temperature is too high,its efficiency and even normal operation will be affected.Therefore,PEMFC thermal management control system was studied in this paper,aiming to control the internal temperature within 353 K through the thermal management control system.The main research contents are as follows.First of all,this paper takes PEMFC’s model,temperature characteristics,thermal management control strategy and method as the entry point to introduce the research status at home and abroad,which lays a theoretical foundation for the following research.This paper describes the basic working principle,physical model and application system of PEMFC,which lays a theoretical foundation for building its simulation model.Secondly,the lumped parameter model of PEMFC output voltage is built in MATLAB/Simulink.The model is composed of Nernst voltage model,activated polarization overvoltage model,ohmic polarization overvoltage model and concentration polarization overvoltage model.The polarization curve and output power curve are obtained through simulation calculation.Moreover,the polarization curves obtained in literature [7] and in this paper are compared and analyzed,and the rationality of the output voltage model in this paper is verified.In addition,by running the 5k W PEMFC model at different working temperatures,the paper further analyzes its temperature characteristics,which lays a theoretical foundation for the establishment of PEMFC thermal management system in the following paper.Finally,according to the control requirements of PEMFC,the control strategy of the thermal management system is formulated,and the control method of the thermal management system is selected.In this paper,PID algorithm,fuzzy PID algorithm and variable domain fuzzy PID algorithm are used to control the system.In addition,based on PID control and single neuron control as the control methods of PEMFC thermal management system,and optimized and improved PEMFC thermal management system control method based on single neuron PID.By comparing and analyzing the simulation results,it is found that the thermal management system based on single neuron PID algorithm has the minimum overshoot and the fastest recovery time.Therefore,when the temperature of PEMFC exceeds 353 K,the control method can make rapid response to the disturbance term of the system and reduce the influence of load change on the temperature of PEMFC.In addition,this paper further studies the PEMFC thermal management control system based on single neuron PID,and uses the fuzzy control theory to optimize the single neuron PID algorithm in the system.The modeling and simulation of PEMFC thermal management system with improved single neuron PID were carried out in MATLAB/Simulink.By comparing and analyzing the simulation results with the simulation results of single neuron PID,the control effect of the improved single neuron PID thermal management system is more significant.