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

As the three major resources for human society to survive,energy,material and information are always going forward together.In the meantime,the evolution of energy and power systems,often bring big innovation to material manufacturing,transformation,transportation,information access,processing and transmission.World development history shows that only to lead the world's energy technology innovation,it is possible to achieve the rise of great powers,so energy development is a national problem that can not be underestimated.As a clean energy,proton exchange membrane fuel cell,since its reaction process does not involve combustion,and its energy conversion efficiency is not limited by the "carrot cycle",except these,it has a lot of outstanding advantages such as high power density,fast start,the switch can be cycled and simple structure and so on.It has become popular products in areas of the power supply,standby power,energy storage and so on.PEMFC is a multi-input multi-output,time-varying,distributed parameter,random interference and multi-coupled complex electrochemical devices,so its detection and control has a certain complexity.It is necessary to carry out in-depth study of PEMFC's monitoring and control system in order to improve the battery performance,speed up its commercialization process,so as to better help the development of human society.In this paper,the working principle of PEMFC is briefly described.And then the fuel cell temperature,gas pressure and module characteristics are described in detail,respectively analyzes the importance of its impact on the performance of fuel cells,finally,the fuel cell subsystem,such as temperature control system,fuel and its circulatory system,oxidant and its circulatory system,control and detection system are detail introduced,discussed their role in the fuel cell system,at the same time pave the way for fuel cell temperature experimental system,temperature control strategy research and single cell voltage monitor system.Temperature as an important factor affecting the performance of fuel cell output,if it is not well controlled,it will cause the electrolyte membrane dehydration,contraction or rupture,even cause the fuel cell "flooded",seriously affect the performance of fuel cells and system security.Therefore,this paper designed the experiment of PEMFC temperature characteristics to analyze it.The fuel cell battery temperature and current density curve at different load voltage can be measured at this experiment,through the detailed analysis of the experimental curve,obtained under different load voltage,the best working temperature and so on.They can provide the basis for the optimal output of fuel cell control,at the same time,the data obtained by the experiment can provide good data support for fuel cell temperature modeling.An empirical model for temperature control of PEMFC was established,through the change and comparison of the model kernel function,the empirical model based on Fourier fitting is most suitable.Simulation experiments were carried out on MATLAB/Simulink simulation platform,by changing the order of fitting,it is concluded that the three fitting models can take into account both the response speed and the control precision.Finally,through the simulation of a large number of data,we can obtain the PEMFC best working temperature-power density curve,Which can provide theoretical guidance for the temperature control and the maximum output power point tracking of the subsequent stack or large battery system.Designed and developed single cell voltage monitor system for the PEMFC described the hardware,software for system in detail.At the same time the system is tested on a 15-cell battery pack,the data measured by the system and FLUKE 87 high-precision digital are compared,this verifies the effectiveness and maneuverability of the system and proves the practical value of the SCVM,which can provide important reference for the stable operation of the fuel cell.