Research On Modeling And Optional Control Of Fuel Cell Supply System

Fuel cell vehicle is one of the important solutions to deal with energy security and new energy strategy.In the 2018 national key R & D plan 4.1,it is clearly proposed that "to break through the integration technology of vehicle power system based on high-power fuel cell engine".Relying on this major special sub topic,the research group of the author focuses on solving the integration process of high-power fuel cell system The key design and control problems of the system provide theoretical guidance for its forward design.It is true that the most direct solution to improve the power density of the fuel cell system is to improve the output capacity of the stack,but the research and development of the stack is subject to the key materials and the corresponding manufacturing process.Therefore,from another perspective,by analyzing the output characteristics of a specific stack,the output capacity of the stack is excavated in depth from the control level,and the power of the stack is improved when the number of individual stacks is constant Rate level is an important technical means to realize the integration of high-power fuel cell system.Based on the output characteristics of a fuel cell stack and the optimal control of air compressor,back pressure valve,hydrogen supply assembly and other components(hereinafter referred to as fuel cell supply circuit system),the energy optimization of the system is studied.The main research contents are as follows:First of all,based on the output characteristics of a fuel cell stack and the basic design parameters of a fuel cell stack,the output voltage simulation model with an activation area of 255cm2 and 370 pieces is established.Aiming at the non independent input variables related to the pressure in the output voltage simulation model,the flow behavior of each component is analyzed and the pressure formation mechanism model is established It integrates with the pressure forming mechanism model to realize the independence of the control input of the reactor.The simulation analysis is carried out for the distribution of the working points and the flow pressure characteristics of the reactor under different characteristics of the electric density.Secondly,from the fuel cell system level,in order to further establish the relationship between the flow field pressure and the supply circuit system,this paper fully discusses the fuel cell supply circuit system scheme and the working process,and proposes the modeling and control demand of the supply circuit.On this basis,the dynamic models of the fuel cell air supply circuit,hydrogen supply circuit and the output characteristics of the fuel cell system are built In atlab / Simulink environment,the characteristics of key components in the supply system are modeled and simulated.The key component model of the supply system is integrated with the reactor model to form a fuel cell reactor supply system simulation environment,which is used to verify the optimization effect of control strategy.Finally,from the fuel cell supply system optimization control level,based on the simulation of the output characteristics of the reactor and the flow pressure characteristics of the supply system,the game process between the parasitic power of the supply system and the output power of the reactor is analyzed,and the pressure of the gas supply system is compensated to optimize the output.For the flow pressure coupling problem in the pressure compensation process,the auto disturbance rejection control(DDC)is used In order to verify the control optimization effect,the control strategy model is integrated with the simulation environment of fuel cell stack supply system,and a joint simulation platform is built to simulate the control optimization effect.