Research On Modeling And Control Strategy Of Fuel Cell Hydrogen Supply System

With the development of science and technology and the improvement of living standard,energy shortage has gradually become a major issue of common concern.Excessive exploitation of traditional fossil fuels has caused energy shortage on the earth and caused environmental pollution.Hydrogen fuel cell is a new type of energy device,which has the advantages of stable operation,no harmful gas and high efficiency.The hydrogen supply system of fuel cell is responsible for supplying the fuel to the anode of the reactor.The recycling of hydrogen and the control of pressure difference are the key problems to be solved to improve the fuel efficiency and ensure the life of the proton exchange membrane.In this paper,the hydrogen supply system of fuel cell of heavy truck is studied.The main research contents are as follows:Based on CHTC-HT working condition calculation truck demand power analysis,the fuel cell stack and hydrogen circulating pump components were selected and the parameters were matched.The principle of hydrogen supply pipe,hydrogen circulation pump,ejector and other system components of fuel cell were analyzed.Based on this,the hydrogen supply system Simulink model was established and verified to ensure the accuracy of the model.For hydrogen supply system of heavy truck’s fuel cell system,ejector size parameters are calculated and the high/low load switch control strategy are designed in this article,coupling of nonlinear system are analyzed.This article designs respectively the PID-feedforward,integral partial linearization state feedback and precise linearization feedback control algorithms for hydrogen supply system,the experimental results show that the accurate linearization feedback algorithm has the best control performance among the three algorithm,which reduces the hydrogen consumption and keep the pressure difference within a stable range.A Luenberger observer based on the partial linearization model of hydrogen supply system is constructed,and the stability of the observer is proved by Lyapunov’s second method.The gain matrix are determined by pole assignment.The observer model was built and simulated.The simulation results show that the hydrogen supply system’s Luenberger observer has high anti-interference performance and the partial pressure of hydrogen was accurately observed.The hardware in loop simulation platform of fuel cell hydrogen supply system was designed,and the control strategy of fuel cell hydrogen supply system was verified and analyzed.The hardware circuit and software code of the controller were designed,and the upper computer software was established to monitor the running status of the hydrogen supply system.Based on the CHTC-HT fuel cell power curve,the hardware in the loop simulation results show that the fuel cell dual-mode switching control strategy can track the vehicle driving demand power better.