Modeling And Control Of Fuel Cell Air Feed System

With the increase in the number and popularity of automobiles,China is facing more and more significant environmental and energy problems.As a new type of power generation device,fuel cell takes hydrogen energy as fuel and converts chemical energy directly into electric energy through electrochemical reaction.It is one of the highest and newest technologies that have a significant impact on human society.The fuel cell is mainly composed of two parts,one is the core of the fuel cell,namely the fuel cell reactor,and the other is the peripheral system that maintains the normal operation of the reactor.the two of which coordinate to work.The main fuel cell systems include gas supply and purge system,water and heat management system,power regulation system,etc.The oxygen pressure of the reaction process plays an important role in the normal operation of the fuel cell.The paper focuses on the fuel cell air feed system,utilizing air compressor rotation speed,gas pipeline pressure,electric reactor pressure and oxygen partial pressure as four state variables,using the energy conservation equation,the ideal gas equation as well as the working mechanism of fuel cell and so on to establish the mathematical model of air feed system,to determine the flow characteristic and power of the core of air compressor,and uses matlab to fit its characteristic curve,to set up a complete air feed system model.And at the same time by analyzing the power curve,we can know that maintain the oxygen excess ratio near 2 or so leads to the best efficiency of system.Finally,I design three kinds of control algorithm,that is,PID,unconstrained dynamic matrix control and dynamic matrix control for regulating air feed system respectively,and carry on the simulation in simulink.Through the simulation results,I analyze the three kinds of excess ratio under the control system.The PID algorithm is better than the model predictive control for the control response time of the system,but it cannot control the trajectory of the system's input and output in the whole control process,but the model predictive control can well limit the range of input and output avoids affecting the normal operation of the system such as causing oxygen starvation,so as to optimize the whole system,to maintain the oxygen excess ratio of the system near 2 or so.