Design Of A Humidity Control System Of PEM Fuel Cell Based On Impedance Monitoring

PEMFC(Proton Exchange Membrane Fuel Cell) is a hermetical system,whose internal humidity is very important for the work efficiency and service life of fuel cell. If the internal humidity of fuel cell can be monitored even controlled,the economic losses caused by the damage of single cells in the abnormal situation will reduce greatly.Therefore,it has important practical significance for solving humidity measurement and designed a kind of effective control system of PEM fuel cell system.This article designs a fuel cell impedance online testing system firstly.Through the elaboration of PEM monolithic battery of fuel cell experimental model and the equivalent circuit model,the analysis of part and the characteristic of the internal fuel-cell PEM,and based on comparison various testing methods of fuel cell home and abroad,We put forward a kind of design scheme of the fuel cells monolithic impedance online testing system which ground on the alternating impedance According to the problems that the PEM fuel cell interior humidity cannot easily be measured directly,the method of humidity soft measurement based on RBF neural network is put forward.The research of soft measurement model selection and secondary variables,data preprocessing methods is also reached,the result of soft measurement model RBF network simulation experiment show that the RBF network in the soft measurement model established in the article can forecast the moisture of galvanic pile PEM in average.On the basis of the soft measurement of the humidity,as well as of the fuzzy control and the basic principle of neural network technology,we has designed a kind of humidity control system.It is a kind of neural network and fuzzy logic theory of composite intelligent control,through the learning ability of neural network to optimize the fuzzy logic rules,so as to realize the experience of the effective control of humidity.This article emulates the electric control system model of humidity on Matlab/Simulink platform.The results show that the humidity control system has well robustness and control quality,it can satisfied the parameter time-variance PEM fuel cell galvanic pile of humidity control system requirements.