Modeling And Control Of Proton Exchange Membrane Fuel Cell Hydrogen Supply System

With the rapid development of automobile industry,cars have increasingly become an indispensable transportation in people’s life.However,automobile exhaust gas contains a lot of harmful substances and seriously pollutes the environment.Under the theme of energy conservation,emission reduction and environmental protection,Environmental protection organizations around the world strongly advocate green travel and countries and government introduces policies to improve automobile emission standards,which promote the development of renewable energy.Under the background,proton exchange membrane fuel cell（PEMFC）emerged as the power core of a new energy engine,which converts the chemical energy generated by the reaction of hydrogen and oxygen directly into electrical energy and the reaction product is water.This fuel cell has the advantages of zero emission,low noise and high efficiency,and is the most reliable alternative to the traditional internal combustion engine.However,the performance of proton exchange membrane fuel cell vehicle is largely dependent on the performance of hydrogen supply system,and a stable and fast hydrogen supply control is very important for it.In this paper,the fuel cell hydrogen supply system is taken as the research object,aiming at the hydrogen supply system and the structure of proportional electromagnetic valve and switch solenoid valve,the following aspects are researched:1.The main structure of the test platform was designed according to the actual hydrogen supply system of fuel cell engine.ECU was used as the system controller to collect sensor signals and send control commands through CAN bus communication.2.According to the experimental platform in laboratory and grasping the main characteristic of hydrogen supply system for the hydrogen fuel cell engine and disturbance caused by the exhaust valve,a oriented control model is established.Owing to the influence of uncertain factors,a back stepping control strategy based on extended state observer is proposed to estimate and compensate the disturbances.Finally,the control strategy is verified by experiments.Experimental results show that the control strategy solves the disturbance effect effectively.The rapidity and stability of the controller are verified under various working conditions.3.In order to reduce the system energy consumption,reduce the system pressure fluctuation and improve control accuracy,according to the hydrogen supply system test platform for PEMFC,the structure of hydrogen supply valve with four switch solenoid valve is studied.Because the working frequency of switch solenoid valve is low,four switch solenoid valve loop-testing is applied in order to improve the working frequency and prolong its working life.And the working curve of the switch solenoid valve is unknown,so its working Map is calibrated and the control-oriented model is established.Since the Map of switching solenoid valve is not accurate enough,an active disturbance rejection control strategy is proposed to solve the problem of model mismatch.Finally,experiments are carried out to verify the performance of the control strategy.Experimental results show that the control strategy has good the capacity of interference and rapidity.